[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"minerals:one:198":3},{"id":4,"longid":5,"guid":6,"name":7,"shortcode_ima":8,"entrytype":9,"entrytype_text":10,"varietyof":11,"synid":8,"polytypeof":8,"groupid":8,"weighting":12,"nolocadd":13,"blacklisted":13,"mindat_formula":14,"mindat_formula_note":8,"ima_formula":8,"elements":15,"sigelements":18,"key_elements":8,"impurities":8,"cim":8,"ima_status":8,"ima_notes":8,"ima_history":8,"approval_year":8,"publication_year":8,"discovery_year":8,"strunz10ed1":19,"strunz10ed2":19,"strunz10ed3":19,"strunz10ed4":8,"dana8ed1":19,"dana8ed2":19,"dana8ed3":19,"dana8ed4":19,"csystem":8,"cclass":8,"spacegroup":8,"spacegroupset":19,"a":8,"b":8,"c":8,"alpha":8,"beta":8,"gamma":8,"aerror":8,"berror":8,"cerror":8,"alphaerror":8,"betaerror":8,"gammaerror":8,"va3":8,"z":8,"csmetamict":13,"commentcrystal":8,"twinning":8,"tranglide":8,"parting":8,"epitaxidescription":8,"morphology":8,"tlform":8,"hmin":8,"hmax":8,"hardtype":8,"vhnmin":19,"vhnmax":19,"vhnerror":8,"vhng":8,"vhns":8,"commenthard":8,"dmeas":19,"dmeas2":19,"dcalc":19,"dmeaserror":8,"dcalcerror":8,"commentdense":8,"lustre":20,"lustretype":20,"commentluster":8,"diapheny":8,"streak":8,"colour":21,"commentcolor":22,"colors":23,"streak_colors":8,"luminescence":8,"uv":8,"cleavage":8,"cleavagetype":8,"fracturetype":8,"tenacity":8,"commentbreak":8,"opticaltype":8,"opticalsign":8,"opticalalpha":8,"opticalalpha2":19,"opticalalphaerror":8,"opticalbeta":8,"opticalbeta2":19,"opticalbetaerror":8,"opticalgamma":8,"opticalgamma2":19,"opticalgammaerror":8,"opticalomega":8,"opticalomega2":19,"opticalomegaerror":8,"opticalepsilon":8,"opticalepsilon2":19,"opticalepsilonerror":8,"opticaln":8,"opticaln2":8,"opticalnerror":8,"optical2vcalc":8,"optical2vcalc2":8,"optical2vcalcerror":8,"optical2vmeasured":8,"optical2vmeasured2":8,"optical2vmeasurederror":8,"rimin":8,"rimax":8,"opticaldispersion":8,"opticalpleochroism":8,"opticalpleochorismdesc":8,"opticalbirefringence":8,"opticalcomments":8,"opticalcolour":8,"opticalinternal":8,"opticaltropic":8,"opticalanisotropism":8,"opticalbireflectance":8,"opticalextinction":8,"opticalr":8,"specdispm":8,"ir":8,"electrical":8,"magnetism":8,"thermalbehaviour":8,"other":8,"industrial":8,"occurrence":8,"otheroccurrence":25,"type_specimen_store":8,"description_short":8,"aboutname":26,"rock_parent":8,"rock_parent2":8,"rock_root":27,"rock_bgs_code":8,"meteoritical_code":8,"updttime":28,"reviewed_at":8,"variety_of":29,"varieties":37,"group_members":41,"associates":42,"confused_with":87,"type_localities":88,"occurrence_total":89,"citations":90,"images":308,"structures":721,"synonyms":722,"language_names":747,"wikidata_qid":8,"texts":748},198,"1:1:198:0","05f4c4db-a552-46a2-91d2-07ac2f73ac4b","Amethyst",null,2,"variety",3337,96626,false,"SiO\u003Csub>2\u003C\u002Fsub>",[16,17],"Si","O",[16,17],"0","Vitreous","Violet - purple","pleochroic: blue-violet to purple",[24],"purple","Very common, in many different environments. The commercially most important occurrences are in volcanic rocks, where amethyst crystals outline former gas cavities. In low and medium temperature hydrothermal veins associated with iron ores. As late overgrowth (\"scepter quartz\") on quartz in pegmatite and alpine-type environments.","From Greek \"a-methystos\", meaning \"not drunk\". In ancient times, it was believed that amethyst warded off drunkenness. Drinking cups were sometimes carved from amethyst. At the same time, the colour of the red wine drunk from these cups is said to have been approximately the same colour as the cups. Therefore, the wine could be diluted with water without the drinker noticing, thinking it was the material of the cup itself that warded off drunkenness.",0,"2026-04-30 17:03:48",{"id":11,"name":30,"entrytype":27,"csystem":31,"ima_formula":14,"mindat_formula":14,"hmin":32,"hmax":32,"dmeas":33,"dcalc":34,"strunz10ed1":35,"primary_image_id":36},"Quartz","Trigonal",7,"2.65","2.66","4",30579,[38],{"id":39,"name":40,"entrytype":9,"csystem":8,"ima_formula":8,"mindat_formula":14,"hmin":8,"hmax":8,"dmeas":8,"dcalc":8,"primary_image_id":8},40451,"Burnt amethyst",[],[43,52,58,69,77],{"id":44,"name":45,"entrytype":27,"csystem":31,"ima_formula":46,"mindat_formula":47,"hmin":48,"hmax":48,"dmeas":49,"dcalc":50,"primary_image_id":51},859,"Calcite","Ca(CO\u003Csub>3\u003C\u002Fsub>)","CaCO\u003Csub>3\u003C\u002Fsub>",3,"2.7102","2.711",4401,{"id":53,"name":54,"entrytype":9,"csystem":8,"ima_formula":8,"mindat_formula":14,"hmin":55,"hmax":32,"dmeas":56,"dcalc":19,"primary_image_id":57},960,"Chalcedony",6.5,"2.6",87926,{"id":59,"name":60,"entrytype":27,"csystem":61,"ima_formula":62,"mindat_formula":63,"hmin":64,"hmax":65,"dmeas":66,"dcalc":67,"primary_image_id":68},1719,"Goethite","Orthorhombic","FeO(OH)","Fe\u003Csup>3+\u003C\u002Fsup>O(OH)",5,5.5,"4.27","4.18",29787,{"id":70,"name":71,"entrytype":27,"csystem":31,"ima_formula":72,"mindat_formula":72,"hmin":64,"hmax":73,"dmeas":74,"dcalc":75,"primary_image_id":76},1856,"Hematite","Fe\u003Csub>2\u003C\u002Fsub>O\u003Csub>3\u003C\u002Fsub>",6,"5.26","5.255",29858,{"id":78,"name":79,"entrytype":27,"csystem":80,"ima_formula":81,"mindat_formula":82,"hmin":83,"hmax":83,"dmeas":84,"dcalc":85,"primary_image_id":86},3988,"Todorokite","Monoclinic","(Na,Ca,K,Ba,Sr)\u003Csub>1-x\u003C\u002Fsub>(Mn,Mg,Al)\u003Csub>6\u003C\u002Fsub>O\u003Csub>12\u003C\u002Fsub> · 3-4H\u003Csub>2\u003C\u002Fsub>O","(Na,Ca,K,Ba,Sr)\u003Csub>1-x\u003C\u002Fsub>(Mn,Mg,Al)\u003Csub>6\u003C\u002Fsub>O\u003Csub>12\u003C\u002Fsub>·3-4H\u003Csub>2\u003C\u002Fsub>O",1.5,"3.67","3.65",24311,[],[],1581,[91,95,99,103,107,110,115,119,123,126,130,133,136,139,143,147,151,154,158,162,166,170,174,178,182,186,189,194,198,202,205,209,213,217,220,223,227,230,234,237,242,246,250,253,257,262,266,270,275,280,284,287,291,295,299,303],{"id":92,"year":93,"html":94,"doi":8},16100228,1823,"Brewster, D. (1823) On circular polarization, as exhibited in the optical structure of the amethyst, with remarks on the distribution of the colouring matter in that mineral. Transactions of the Royal Society of Edinburgh: 9: 139-152.",{"id":96,"year":97,"html":98,"doi":8},16100229,1847,"Haidinger, W. (1847) Ueber den Pleochroismus des Amethysts. Annalen der Physik: 146: 531-544.",{"id":100,"year":101,"html":102,"doi":8},16100230,1906,"Berthelot, M. (1906) Synthèse du quartz améthyste; recherches sur la teinture naturelle ou artificielle de quelques pierres précieuses sou les influences radioactives. Comptes Rendus de l'Académie des Sciences: 143: 477-488. [Synthesis of amethyst quartz. Researches on the color, natural or artificial, of some precious stones under radioactive influences.]",{"id":104,"year":105,"html":106,"doi":8},519381,1925,"Holden, Edward F. (1925) The cause of color in smoky quartz and amethyst. \u003Ci>American Mineralogist\u003C\u002Fi>,  10 (9) 203-252 \u003Ca target='_blank' href='http:\u002F\u002Fwww.minsocam.org\u002Fammin\u002FAM10\u002FAM10_203.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":108,"year":105,"html":109,"doi":8},16100232,"Raman, C.V., Banerji, K. (1925) The optical properties of amethyst. Transactions of the Optical Society: 26: 289-292.",{"id":111,"year":112,"html":113,"doi":114},104699,1932,"Mügge, O. (1932) Zwillingsbau amethystartiger Quarze mit Rücksicht auf ihre Entstehungstemperatur. \u003Ci>Zeitschrift für Kristallographie\u003C\u002Fi>,  83 (1-6). 460-484 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1524\u002Fzkri.1932.83.1.460'>doi:10.1524\u002Fzkri.1932.83.1.460\u003C\u002Fa>","10.1524\u002Fzkri.1932.83.1.460",{"id":116,"year":117,"html":118,"doi":8},16100234,1934,"Frondel, C. (1934) Origin of the segmental coloration of amethyst and smoky quartz. American Museum Novitates: 758: 1-15.",{"id":120,"year":121,"html":122,"doi":8},16100235,1952,"Bappu, M.K.V. (1952) Spectroscopic study of amethyst quartz in the visible region. Indian Journal of Physics: 26: 1-14.",{"id":124,"year":121,"html":125,"doi":8},16100236,"Bappu, M.K.V. (1952) Spectroscopic study of amethyst quartz in the ultraviolet and infrared regions. Indian Journal of Physics: 26: 385-392.",{"id":127,"year":128,"html":129,"doi":8},16100237,1954,"Pancharatnam, S. (1954) On the pleochroism of amethyst quartz and its absorption spectra. Proceedings of the Indian Academy of Sciences - Section A: 40:196-210.",{"id":131,"year":128,"html":132,"doi":8},16100238,"Raman, C.V, Jayaraman, A. (1954) The structure of amethyst quartz and the origin of its pleochroism. Proceedings of the Indian Academy of Sciences, Section A: 40: 189-195.",{"id":134,"year":128,"html":135,"doi":8},16100239,"Raman, C.V, Jayaraman, A. (1954) The structure of amethyst quartz and its genesis in nature. Proceedings of the Indian Academy of Sciences, Section A: 40: 221-229.",{"id":137,"year":128,"html":138,"doi":8},16100240,"Rose, H., Lietz, J. (1954) Ein grün verfärbbarer Amethyst. Naturwissenschaften: 41: 448.",{"id":140,"year":141,"html":142,"doi":8},522853,1956,"Cohen, Alvin J. (1956) Color centers in the α-quartz called amethyst. \u003Ci>American Mineralogist\u003C\u002Fi>,  41 (11-12) 874-891 \u003Ca target='_blank' href='http:\u002F\u002Fwww.minsocam.org\u002Fammin\u002FAM41\u002FAM41_874.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":144,"year":145,"html":146,"doi":8},16100242,1957,"Lietz, J., Münchberg, W. (1957) The coloring of amethyst. II. The effect of ultraviolet and gamma-rays on the coloring. Neues Jahrbuch für Mineralogie, Monatshefte: 1957: 25-33.",{"id":148,"year":149,"html":150,"doi":8},16100243,1958,"Pancharatnam, S. (1958) The optic interference figures of amethystine quartz. Part I. Proceedings of the Indian Academy of Sciences, Section A: 47: 201-209.",{"id":152,"year":149,"html":153,"doi":8},16100244,"Pancharatnam, S. (1958) The optic interference figures of amethystine quartz. Part II. Proceedings of the Indian Academy of Sciences, Section A: 47: 220-229.",{"id":155,"year":156,"html":157,"doi":8},16100245,1961,"Chudoba, K.F. (1961) The significance of the color of amethyst. Aufschluss: 12: 233-248 (in German).",{"id":159,"year":160,"html":161,"doi":8},16100246,1962,"Chudoba, K.F. (1962) Some relations between the causes of amethyst, smoky quartz, and citrine colors as given by modern science. Mineralogicheskii Sbornik (Lvov): 16: 91-105.",{"id":163,"year":164,"html":165,"doi":8},16100248,1966,"McLaren, A.C., Phakey, P.P. (1966) Electron microscope study of Brazil twin boundaries in amethyst. Physica Status Solidi: 13: 413-422.",{"id":167,"year":164,"html":168,"doi":169},2230887,"Lehmann, G., Moore, W. J. (1966) Color Center in Amethyst Quartz. \u003Ci>Science\u003C\u002Fi>, 152 (3725). 1061-1062 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1126\u002Fscience.152.3725.1061'>doi:10.1126\u002Fscience.152.3725.1061\u003C\u002Fa>","10.1126\u002Fscience.152.3725.1061",{"id":171,"year":172,"html":173,"doi":8},16100249,1967,"Lehmann, G. (1967) Iron color center as the cause of amethyst color. Zeitschrift für Naturforschung, Teil A:  Astrophysik, Physik und Physikalische Chemie: 22: 2080-2085.",{"id":175,"year":176,"html":177,"doi":8},16100250,1972,"Dennen, W.H., Puckett, A.M. (1972) On the chemistry and color of amethyst. The Canadian Mineralogist: 11: 448-456.",{"id":179,"year":180,"html":181,"doi":8},16100251,1973,"Lehmann, G., Bambauer, H.U. (1973) Quartz crystals and their colors. Angewandte Chemie International Edition: 12: 283-290.",{"id":183,"year":184,"html":185,"doi":8},526310,1974,"Hassan, F., Cohen, and Alvin J. (1974) Biaxial color centers in amethyst quartz. \u003Ci>American Mineralogist\u003C\u002Fi>,  59 (7-8) 709-718 \u003Ca target='_blank' href='http:\u002F\u002Fwww.minsocam.org\u002Fammin\u002FAM59\u002FAM59_709.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":187,"year":184,"html":188,"doi":8},526311,"Cohen, Alvin J., Hassan, and F. (1974) Ferrous and ferric ions in synthetic α-quartz and natural amethyst. \u003Ci>American Mineralogist\u003C\u002Fi>,  59 (7-8) 719-728 \u003Ca target='_blank' href='http:\u002F\u002Fwww.minsocam.org\u002Fammin\u002FAM59\u002FAM59_719.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":190,"year":191,"html":192,"doi":193},151256,1982,"McLaren, A. C., Pitkethly, D. R. (1982) The twinning microstructure and growth of amethyst quartz. \u003Ci>Physics and Chemistry of Minerals\u003C\u002Fi>,  8 (3) 128-135 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1007\u002Fbf00311283'>doi:10.1007\u002Fbf00311283\u003C\u002Fa>","10.1007\u002Fbf00311283",{"id":195,"year":196,"html":197,"doi":8},16100255,1984,"Neumann, E., Schmetzer, K. (1984) Mechanism of thermal-conversion of color and color-centers by heat-treatment of amethyst. Neues Jahrbuch für Mineralogie Monatshefte: 6: 272-282.",{"id":199,"year":200,"html":201,"doi":8},528183,1985,"Cohen, Alvin J. (1985) Amethyst color in quartz, the result of radiation protection involving iron. \u003Ci>American Mineralogist\u003C\u002Fi>,  70 (11-12) 1180-1185 \u003Ca target='_blank' href='http:\u002F\u002Fwww.minsocam.org\u002Fammin\u002FAM70\u002FAM70_1180.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":203,"year":200,"html":204,"doi":8},16100258,"Currier, R.H. (1985) Natural fading of amethyst. Gems & Gemology: 21(2): 115-116.",{"id":206,"year":207,"html":208,"doi":8},16100259,1986,"Adekeye, J.J.D, Cohen, A.J. (1986) Correlation of Fe\u003Csup>4+\u003C\u002Fsup> optical anisotropy, Brazil twinning and channels in the basal plane of amethyst quartz. Applied Geochemistry: 1: 153-160.",{"id":210,"year":207,"html":211,"doi":212},16100256,"Balitsky, Vladimir S., Balitskaya, Olga V. (1986) The amethyst-citrine dichromatism in quartz and its origin. \u003Ci>Physics and Chemistry of Minerals\u003C\u002Fi>,  13 (6). 415-421 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1007\u002Fbf00309187'>doi:10.1007\u002Fbf00309187\u003C\u002Fa>","10.1007\u002Fbf00309187",{"id":214,"year":215,"html":216,"doi":8},16100260,1987,"Baran, Z., Godwod, K., Warminski, T. (1987) X-ray study of Brazil twins in natural amethyst. Physica Status Solidi: 101: 9-24.",{"id":218,"year":215,"html":219,"doi":8},16100261,"Kostov, R. (1987) A discussion on the color of amethyst. Priroda (Sofia): 36(2):  10-15.",{"id":221,"year":215,"html":222,"doi":8},16100262,"Schmetzer, K. (1987) Microscopic observation of twinning microstructure in natural amethyst. Neues Jahrbuch für Mineralogie, Monatshefte: 8-15.",{"id":224,"year":225,"html":226,"doi":8},16100263,1988,"Epstein, D.S. (1988) Amethyst mining in Brazil. Gems & Gemmology: 44: 214-228.",{"id":228,"year":225,"html":229,"doi":8},16100264,"Martin, B., Röller, K., Flörke, O.W. (1988) Über die polysynthetische Rechts-Links-Verzwilligung von Amethyst-Quarz und der mikrokristallinen Quarzspezies Chalzedon und Quarzin. Zeitschrift für Kristallographie: 182: 179-180.",{"id":231,"year":232,"html":233,"doi":8},12908297,1989,"Cohen, Alvin J. (1989) New Data on the Cause of Smoky and Amethystine Color in Quartz. \u003Ci>The Mineralogical Record\u003C\u002Fi>, 20 (5) 365-367",{"id":235,"year":232,"html":236,"doi":8},16100266,"Stegger, P., Lehmann, G. (1989) The structures of three centers of trivalent iron in α-quartz. Physics and Chemistry of Minerals: 16: 401-407.",{"id":238,"year":239,"html":240,"doi":241},151874,1990,"Taijing, Lu, Sunagawa, Ichiro (1990) Structure of Brazil twin boundaries in amethyst showing brewster fringes. \u003Ci>Physics and Chemistry of Minerals\u003C\u002Fi>,  17 (3) 207-211 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1007\u002Fbf00201451'>doi:10.1007\u002Fbf00201451\u003C\u002Fa>","10.1007\u002Fbf00201451",{"id":243,"year":244,"html":245,"doi":8},16100268,1993,"Choh, S.H., Jo, S.H., Song, K.J., Park, I.W., Han, C.S. (1993) Thermal stability of iron(3+) centers in natural and synthetic amethyst. Bulletin of Magnetic Resonance: 15: 35-40.",{"id":247,"year":248,"html":249,"doi":8},15939947,1994,"Lieber, W. (1994) Amethyst - Geschichte, Eigenschaften, Fundorte. Christian Weise Verlag, München.",{"id":251,"year":248,"html":252,"doi":8},16100270,"Rossman, G.R. (1994) The colored varieties of the silica minerals. In: P.J. Haney, ed., Reviews in Mineralogy 29, 433-468.",{"id":254,"year":248,"html":255,"doi":256},531506,"Vasconcelos, Paulo M., Wenk, Hans-Rudolf, Rossman, George R. (1994) The Anahí Ametrine Mine, Bolivia. \u003Ci>Gems & Gemology\u003C\u002Fi>,  30 (1) 4-23 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.5741\u002Fgems.30.1.4'>doi:10.5741\u002Fgems.30.1.4\u003C\u002Fa>","10.5741\u002Fgems.30.1.4",{"id":258,"year":259,"html":260,"doi":261},531704,1999,"Balitsky, Vladimir S., Lu, Taijin, Rossman, George R., Makhina, Irina B., Mar'in, Anatolii A., Shigley, James E., Elen, Shane, Dorogovin, Boris A. (1999) Russian Synthetic Ametrine. \u003Ci>Gems & Gemology\u003C\u002Fi>,  35 (2) 122-134 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.5741\u002Fgems.35.2.122'>doi:10.5741\u002Fgems.35.2.122\u003C\u002Fa>","10.5741\u002Fgems.35.2.122",{"id":263,"year":264,"html":265,"doi":8},16100272,2004,"Dedushenko, S.K., Makhina, I.B., Mar'in, A.A., Mukhanov, V.A., Perfiliev, Y.D. (2004) What oxidation state of iron determines the amethyst colour? Hyperfine Interactions: 156\u002F157: 417-422.",{"id":267,"year":264,"html":268,"doi":269},531900,"Balitsky, Vladimir S., Balitsky, Denis V., Bondarenko, Galina V., Balitskaya, Olga V. (2004) The 3543 cm\u003Csup>-1\u003C\u002Fsup> Infrared Absorption Band in Natural and Synthetic Amethyst and Its Value In Identification. \u003Ci>Gems & Gemology\u003C\u002Fi>,  40 (2) 146-161 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.5741\u002Fgems.40.2.146'>doi:10.5741\u002Fgems.40.2.146\u003C\u002Fa>","10.5741\u002Fgems.40.2.146",{"id":271,"year":272,"html":273,"doi":274},16696,2005,"Karampelas, S., Fritsch, E., Zorba, T., Paraskevopoulos, K. M., Sklavounos, S. (2005) Distinguishing natural from synthetic amethyst: the presence and shape of the 3595 cm−1 peak. \u003Ci>Mineralogy and Petrology\u003C\u002Fi>,  85 (1) 45-52 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1007\u002Fs00710-005-0101-9'>doi:10.1007\u002Fs00710-005-0101-9\u003C\u002Fa>","10.1007\u002Fs00710-005-0101-9",{"id":276,"year":277,"html":278,"doi":279},597459,2007,"Karampelas, S., Fritsch, E., Zorba, T., Paraskevopoulos, K. M., Sklavounos, S. (2007) AN UPDATE IN THE SEPARATION OF NATURAL FROM SYNTHETIC AMETHYSTS. \u003Ci>Bulletin of the Geological Society of Greece\u003C\u002Fi>,  40 (2) 805 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.12681\u002Fbgsg.16721'>doi:10.12681\u002Fbgsg.16721\u003C\u002Fa>","10.12681\u002Fbgsg.16721",{"id":281,"year":282,"html":283,"doi":8},16100273,2008,"Balzer, Reinhard (2008) \u003Ci>Amethyst Uruguay\u003C\u002Fi>. Christian Weise Verlag.",{"id":285,"year":282,"html":286,"doi":8},16100274,"Tumuklu, A., Gumus, H., Sen, S. (2008)  Role of trace elements in natural amethysts in colouring. Asian Journal of Chemistry: 20: 4138-4140.",{"id":288,"year":289,"html":290,"doi":8},16138249,2009,"Lameiras, F.S., Nunes, E.H.M., Vasconcelos, W.L. (2009) Infrared and Chemical Characterization of Natural Amethysts and Prasiolites Colored by Irradiation. Materials Research, 12(3), 315-320.",{"id":292,"year":293,"html":294,"doi":8},16100276,2011,"Russo, F.T. (2011) Investigation of optical, electrical and structural properties in Amethyst. Dissertation (Master in Science and Technology of Materials), UNESP, FC, Bauru, 113pp, (in Portugese).",{"id":296,"year":293,"html":297,"doi":298},532183,"Karampelas, Stefanos, Fritsch, Emmanuel, Zorba, Triantafillia, Paraskevopoulos, Konstantinos M. (2011) Infrared Spectroscopy of Natural vs. Synthetic Amethyst: An Update. \u003Ci>Gems & Gemology\u003C\u002Fi>,  47 (3) 196-201 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.5741\u002Fgems.47.3.196'>doi:10.5741\u002Fgems.47.3.196\u003C\u002Fa>","10.5741\u002Fgems.47.3.196",{"id":300,"year":301,"html":302,"doi":8},16100277,2012,"Gilg, H.A., Liebtrau, S., Staebler, G.A., Wilson, T. (editors) (2012) Amethyst: Uncommon Vintage ExtraLapis English No.16, Lithographie. Denver 124pp.",{"id":304,"year":305,"html":306,"doi":307},7734914,2018,"Klemme, Stephan, Berndt, Jasper, Mavrogonatos, Constantinos, Flemetakis, Stamatis, Baziotis, Ioannis, Voudouris, Panagiotis, Xydous, Stamatios (2018) On the color and genesis of prase (green quartz) and amethyst from the Island of Serifos, Cyclades, Greece. \u003Ci>Minerals\u003C\u002Fi>,  8 (11) 487 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.3390\u002Fmin8110487'>doi:10.3390\u002Fmin8110487\u003C\u002Fa> \u003Ca target='_blank' href='https:\u002F\u002Fwww.mdpi.com\u002F2075-163X\u002F8\u002F11\u002F487\u002Fpdf?version=1540536930' class='refpdflink'>\u003C\u002Fa>","10.3390\u002Fmin8110487",[309,319,329,338,347,356,365,374,384,389,399,408,418,426,435,444,451,461,469,478,486,493,501,510,519,526,534,542,549,556,563,570,579,586,595,604,611,620,626,634,641,648,656,663,671,678,685,692,700,707,714],{"id":310,"source_url":311,"license_code":312,"credit_html":313,"title":314,"description":315,"author":316,"original_width":317,"original_height":318},32560,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6911957","CC BY-SA 4.0","Didier Descouens, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6911957\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst sceptre2.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa> \n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality :  Mun. Las Vigas de Ramírez (Mun. de Profesor Rafael Ramírez), Veracruz, Mexico\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>Size : 5x3x3cm\u003C\u002Fdd>\u003C\u002Fdl>","Didier Descouens",2893,3552,{"id":320,"source_url":321,"license_code":322,"credit_html":323,"title":324,"description":325,"author":326,"original_width":327,"original_height":328},32561,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=7515666","CC BY-SA 3.0","JJ Harrison (https:\u002F\u002Fjjharrison.com.au\u002F), via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=7515666\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst. Magaliesburg, South Africa.jpg","Amethyst specimen from Magaliesburg, South Africa.","JJ Harrison (https:\u002F\u002Fjjharrison.com.au\u002F)",2016,1344,{"id":330,"source_url":331,"license_code":322,"credit_html":332,"title":333,"description":334,"author":335,"original_width":336,"original_height":337},32563,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=17469966","Mauro Cateb, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=17469966\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst pebbles.jpg","Amethyst (violet quartz) pebbles. Photo : Mauro Cateb","Mauro Cateb",4320,3240,{"id":339,"source_url":340,"license_code":312,"credit_html":341,"title":342,"description":343,"author":344,"original_width":345,"original_height":346},32566,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=132610884","Eric Polk, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=132610884\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz var Amethyst NHMLA.png","Sample of Amethyst collected from Santa Margarita Mine, Guerero, Mexico. On display at the Natural History Museum of Los Angeles County, Los Angeles, California, USA.","Eric Polk",1693,2626,{"id":348,"source_url":349,"license_code":312,"credit_html":350,"title":351,"description":352,"author":353,"original_width":354,"original_height":355},32567,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=138613295","Geolina163, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=138613295\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Joanneum Naturkundemuseum Amethyst Mexiko.jpg","Universalmuseum Joanneum_Naturkundemuseum: Amethyst (Mexiko)","Geolina163",3624,2868,{"id":357,"source_url":358,"license_code":312,"credit_html":359,"title":360,"description":361,"author":362,"original_width":363,"original_height":364},32568,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=155328479","Ludvig14, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=155328479\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst-geode both 020 7766.jpg","Amethyst geode in hidden and open forms","Ludvig14",5533,3689,{"id":366,"source_url":367,"license_code":312,"credit_html":368,"title":369,"description":370,"author":371,"original_width":372,"original_height":373},32570,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=157389222","W.carter, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=157389222\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Raw amethyst crystals 3.jpg","A cluster of purple raw amethyst crystals. Studio photography in Vibble, Visby, Gotland, Sweden.","W.carter",3800,2905,{"id":375,"source_url":376,"license_code":377,"credit_html":378,"title":379,"description":380,"author":381,"original_width":382,"original_height":383},32571,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=159652132","CC BY 4.0","Artyom Svetlov, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=159652132\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Moscow State University amethyst 2014-01 1389529268.JPG","amethyst","Artyom Svetlov",3072,2048,{"id":385,"source_url":386,"license_code":377,"credit_html":387,"title":388,"description":380,"author":381,"original_width":382,"original_height":383},32572,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=159705830","Artyom Svetlov, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=159705830\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Moscow State University amethyst 2014-01 1389531004.JPG",{"id":390,"source_url":391,"license_code":392,"credit_html":393,"title":394,"description":395,"author":396,"original_width":397,"original_height":398},32573,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=160042214","CC0 1.0","RegionVisitor90, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=160042214\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst @ Woodsie’s Gem Shop, Nichols Point 20250215-123601.jpg","This Violet quartz specimen weighs 250kg from Brazil\n\u003Cp>Amethyst is a variety of Quartz and can sometimes be found in geodes like this example.\n\u003C\u002Fp>\u003Cp>Geodes are formed when bubbles of liquid or gas form in cooling magma, creating voids. The crystals slowly grow inwards and the rock surround protects the crystals, thus allowing them to grow much bigger than normally be possible.\nThis particular specimen is from Brazil.\n\u003C\u002Fp>\nIt weights 1\u002F4 of a tonne and took 5 men to lift it in its current position.","RegionVisitor90",4032,3024,{"id":400,"source_url":401,"license_code":392,"credit_html":402,"title":403,"description":404,"author":405,"original_width":406,"original_height":407},32574,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=162642282","Lodewicus de Honsvels, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=162642282\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst, Zempléni-hegység, Ungarn.jpg","\u003Ca href=\"https:\u002F\u002Fde.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"de:Amethyst\">Amethyst\u003C\u002Fa> aus Zempléni-hegység, Ungarn, in einer Ausstellungsvitrine im \u003Ca href=\"https:\u002F\u002Fde.wikipedia.org\u002Fwiki\u002FMuseum_Mineralogia_M%C3%BCnchen\" class=\"extiw\" title=\"de:Museum Mineralogia München\">Museum Mineralogia München\u003C\u002Fa>","Lodewicus de Honsvels",3448,3668,{"id":409,"source_url":410,"license_code":411,"credit_html":412,"title":413,"description":414,"author":415,"original_width":416,"original_height":417},32575,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=167910186","CC BY 2.0","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=167910186\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst (faceted) (Sebago Pluton, Early Permian, ~293 Ma; Deer Hill, north of Stow, Maine, USA) 9.jpg","Amethyst gemstone from Maine, USA. (71 carats; Maine Mineral & Gem Museum collection, Bethel, Maine, USA)\n\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.  At its simplest, a mineral is a naturally-occurring solid chemical.  Currently, there are over 6100 named and described minerals - about 200 of them are common and about 20 of them are very common.  Mineral classification is based on anion chemistry.  Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.\n\u003C\u002Fp>\u003Cp>The silicates are the most abundant and chemically complex group of minerals.  All silicates have silica as the basis for their chemistry.  \"Silica\" refers to SiO2 chemistry.  The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4.  Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens \"belong\" to each silicon.  The resulting formula for silica is thus SiO2, not SiO4.\n\u003C\u002Fp>\u003Cp>The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2).  All other silicates have silica + impurities.  Many silicates have a significant percentage of aluminum (the aluminosilicates).\n\u003C\u002Fp>\u003Cp>Quartz (silicon dioxide\u002Fsilica - SiO2) is the most common mineral in the Earth's crust.  It is composed of the two most abundant elements in the crust - oxygen and silicon.  It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture.  Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc.\n\u003C\u002Fp>\u003Cp>Purple quartz is called amethyst.  The coloring agent for amethyst is not agreed upon.  Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Exhibit info.\n\u003C\u002Fp>\u003Cp>MAINE AMETHYST\n\u003C\u002Fp>\u003Cp>There are over a dozen locations in Maine where amethyst is reported to occur, but few have produced significant quantities of this purple mineral.\n\u003C\u002Fp>\u003Cp>Notably, these include the quarries \u002F pits around Colton and Deer Hill in Stow, all pegmatite deposits, and the Saltman Prospect in Sweden, a hydrothermal deposit.\n\u003C\u002Fp>\u003Cp>AMETHYST QUICK FACTS\n\u003C\u002Fp>\u003Cp>Amethyst is the purple variety of the mineral quartz.\n\u003C\u002Fp>\u003Cp>Mineral formula for quartz: SiO2.\n\u003C\u002Fp>\u003Cp>The name is derived from the Greek a-methystos, meaning \"not drunk\", as it was believed that amethyst prevented intoxication.\n\u003C\u002Fp>\u003Cp>Amethyst is the February birthstone.\n\u003C\u002Fp>\u003Cp>Amethyst gets its purple color from trace amounts of iron in the quartz structure.\n\u003C\u002Fp>\u003Cp>After tourmaline, amethyst is the second most popular gemstone from Maine.\n\u003C\u002Fp>\u003Cp>In Maine, amethyst is found in granitic pegmatites and hydrothermal deposits.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Geologic unit: Deer Hill Pegmatite, Sebago Pluton, Oxford Pegmatite Field, early Early Permian, ~293 Ma\n\u003C\u002Fp>\u003Cp>Locality: Deer Hill, north of the town of Stow, southwestern Maine, USA\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Locality info.:\nwww.mindat.org\u002Floc-4613.html\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo galleries of quartz and amethyst:\nwww.mindat.org\u002Fgallery.php?min=3337\nand\n\u003C\u002Fp>\nwww.mindat.org\u002Fgallery.php?min=198","James St. John",827,1194,{"id":419,"source_url":420,"license_code":377,"credit_html":421,"title":422,"description":423,"author":371,"original_width":424,"original_height":425},32577,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=170307179","W.carter, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=170307179\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Four faceted amethysts 1.jpg","Four oval faceted amethyst gemstones. Studio photography in Tuntorp, Brastad, Lysekil Municipality, Sweden.",2060,1159,{"id":427,"source_url":428,"license_code":377,"credit_html":429,"title":430,"description":431,"author":432,"original_width":433,"original_height":434},32579,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=181230710","Marie-Lan Taÿ Pamart, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=181230710\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst octopus netsuke Caillois Donation MNHN.jpg","Amethyst netsuke with an octopus entwined in lotus leaves, attributed to Sakiyo Kurokawa Masahide (mid 18th century). Exhibition “Stones and Reveries: The Poetry and Minerals of Roger Caillois“ at the School of Jewelry Arts in Paris (November 6th, 2025—29th, 2026). Gallery of Mineralogy and Geology of the French National Museum of Natural History in Paris.","Marie-Lan Taÿ Pamart",3453,3455,{"id":436,"source_url":437,"license_code":392,"credit_html":438,"title":439,"description":440,"author":441,"original_width":442,"original_height":443},32581,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=188200789","Slashme, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=188200789\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst Jos Plateau 02.jpg","Amethyst from the Jos Plateau, Nigeria","Slashme",4640,5725,{"id":445,"source_url":446,"license_code":392,"credit_html":447,"title":448,"description":449,"author":441,"original_width":450,"original_height":442},32582,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=188200790","Slashme, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=188200790\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst Jos Plateau 01.jpg","Amethyst from the Jos Plateau, Nigeria - Maßstab: mm",3833,{"id":452,"source_url":453,"license_code":454,"credit_html":455,"title":456,"description":457,"author":458,"original_width":459,"original_height":460},32590,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6601888","Public domain","Géry PARENT, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6601888\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz 21.jpg","quartz var. amethyst : Vernet-la-Varenne, Vernet-la Varenne, Arrondissement d’Issoire, Département du Puy-de-Dôme, Auvergne- Rhône-Alpes, France","Géry PARENT",4288,2848,{"id":462,"source_url":463,"license_code":392,"credit_html":464,"title":465,"description":466,"author":405,"original_width":467,"original_height":468},37710,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=162644814","Lodewicus de Honsvels, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=162644814\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Kaktus-Amethyst-Magaliesberge, Südafrika.jpg","„Kaktus“-\u003Ca href=\"https:\u002F\u002Fde.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"de:Amethyst\">Amethyst\u003C\u002Fa> aus den Magaliesbergen, Südafrika in einer Ausstellungsvitrine im \u003Ca href=\"https:\u002F\u002Fde.wikipedia.org\u002Fwiki\u002FMuseum_Mineralogia_M%C3%BCnchen\" class=\"extiw\" title=\"de:Museum Mineralogia München\">Museum Mineralogia München\u003C\u002Fa>",3468,4624,{"id":470,"source_url":471,"license_code":322,"credit_html":472,"title":473,"description":474,"author":475,"original_width":476,"original_height":477},78387,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10145691","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10145691\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-149227.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Municipio Las Vigas de Ramírez (Municipio de Profesor Rafael Ramírez), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FVeracruz\" class=\"extiw\" title=\"en:Veracruz\">Veracruz\u003C\u002Fa>, Mexico (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-5378.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 10.1 x 8.9 x 5.1 cm.\u003C\u002Fdd>\n\u003Cdd>Las Vigas amethysts are among those 5 or 6 localities that serious collector actually collect, cue to their fineness. This one has a special distinction, in that there are two very distinct sceptered crystals right in the center of the specimen. The crystals have the fine purple \"blush\" that makes these so desirable. Ex. Hauck Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>","Robert M. Lavinsky",600,537,{"id":479,"source_url":480,"license_code":322,"credit_html":481,"title":482,"description":483,"author":475,"original_width":484,"original_height":485},78388,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10147422","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10147422\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-159827.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Pennoyer Amethyst Mine (Rainbow lode claim), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FRed_Feather_Lakes,_Colorado\" class=\"extiw\" title=\"en:Red Feather Lakes, Colorado\">Red Feather Lakes\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FLarimer_County,_Colorado\" class=\"extiw\" title=\"en:Larimer County, Colorado\">Larimer County\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FColorado\" class=\"extiw\" title=\"en:Colorado\">Colorado\u003C\u002Fa>, USA (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-18326.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 4.5 x 2.3 x 1.9 cm.\u003C\u002Fdd>\n\u003Cdd>A very unusual sceptred quartz, with some kind of funny twinning or other habit at the termination...just a bizarre piece. Ex. Richard Hauck Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",254,400,{"id":487,"source_url":488,"license_code":322,"credit_html":489,"title":490,"description":491,"author":475,"original_width":492,"original_height":476},78389,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10149424","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10149424\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-169729.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 7.5 x 2.4 x 2.3 cm.\u003C\u002Fdd>\n\u003Cdd>A very unusual and stunning amethyst crystal from Brandberg, very different from the norm. This doubly-terminated crystal, with subtle sceptering, has an incredibly intense purple color with overtones of scarlet.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",292,{"id":494,"source_url":495,"license_code":322,"credit_html":496,"title":497,"description":498,"author":475,"original_width":499,"original_height":500},78393,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10430172","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10430172\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-d49a.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Aggregate Industries Quarry (Simeone Quarry), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FWrentham\" class=\"extiw\" title=\"en:Wrentham\">Wrentham\u003C\u002Fa>, Norfolk County, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FMassachusetts\" class=\"extiw\" title=\"en:Massachusetts\">Massachusetts\u003C\u002Fa>, USA (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-6746.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: thumbnail, 2.6 x 1.8 x 1.5 cm\n\u003Cdl>\u003Cdt>Amethyst\u003C\u002Fdt>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>Sharp and aesthetic, this doubly-terminated Amethyst scepter is gemmy and has a superb luster. Considering that it is from a small location, this is quite a marvelous thumb. 2.6 x 1.8 x 1.5 cm\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",620,800,{"id":502,"source_url":503,"license_code":322,"credit_html":504,"title":505,"description":506,"author":507,"original_width":508,"original_height":509},78405,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=15055648","Parent Géry, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=15055648\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Améthyste sceptre (Madagascar) 1.JPG","quartz var. amethyst, quartz var. white quartz : Tsitondroina Commune, Ikalamavony District Pegmatite Field, Matsiatra Region, Fianarantsoa Procince, Madagascar","Parent Géry",2674,4042,{"id":511,"source_url":512,"license_code":411,"credit_html":513,"title":514,"description":515,"author":516,"original_width":517,"original_height":518},32565,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=105251203","MAURO CATEB from Brazil, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=105251203\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Brazilian amethysts (6330378228).jpg","Amethyst or purple quartz ( quartz or silicon dioxide).","MAURO CATEB from Brazil",2706,2544,{"id":520,"source_url":521,"license_code":322,"credit_html":522,"title":523,"description":524,"author":475,"original_width":525,"original_height":476},2419,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10141484","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10141484\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-131593.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 6.8 x 1.8 x 1.8 cm.\u003C\u002Fdd>\n\u003Cdd>A superb doubly-terminated, complete and undamaged floater of Brandberg amethyst, with what appears to be an internal SCEPTERED phantom! It has a gorgeous \"blush\" of purple inside, which makes these crystals so unique. This is not only a very fine Brandberg amethyst, but a very distinctive and unusual one as well! Among the better doubly-terminated floaters I have had. Ex. Charlie Key Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",310,{"id":527,"source_url":528,"license_code":411,"credit_html":529,"title":530,"description":531,"author":516,"original_width":532,"original_height":533},3863,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=105251138","MAURO CATEB from Brazil, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=105251138\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst pebbles (6390216997).jpg","Amethyst or purple quartz.",2032,1545,{"id":535,"source_url":536,"license_code":322,"credit_html":537,"title":538,"description":539,"author":475,"original_width":540,"original_height":541},4854,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162303","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162303\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-221291.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Gold Lake Mine, Little Giant Basin, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSilverton\" class=\"extiw\" title=\"en:Silverton\">Silverton\u003C\u002Fa>, Silverton District, San Juan County, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FColorado\" class=\"extiw\" title=\"en:Colorado\">Colorado\u003C\u002Fa>, USA (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-204313.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 7.5 x 5.0 x 3.1 cm.\u003C\u002Fdd>\n\u003Cdd>A lovely crystal group of cathedral Quartz prisms with very pale Amethyst (\"Amethystine\") tapered terminations from the Gold Lake mine. It is an aesthetic specimen with attractive crystals that are water clear at the tips. Ex. Jaime Bird Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",514,432,{"id":543,"source_url":544,"license_code":322,"credit_html":545,"title":546,"description":539,"author":475,"original_width":547,"original_height":548},4855,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162304","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162304\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-221292.jpg",405,360,{"id":550,"source_url":551,"license_code":322,"credit_html":552,"title":553,"description":554,"author":475,"original_width":555,"original_height":500},7846,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10152366","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10152366\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-178964.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FTurkana_District\" class=\"extiw\" title=\"en:Turkana District\">Turkana District\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FRift_Valley_Province\" class=\"extiw\" title=\"en:Rift Valley Province\">Rift Valley Province\u003C\u002Fa>, Kenya (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-153772.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 32.3 x 9.7 x 8.4 cm.\u003C\u002Fdd>\n\u003Cdd>It would be hard to think of a quartz specimen much more impressive than this one: a gigantic, complete floater amethystine crystal that is multiply-sceptred at both ends. All a long the side faces are interesting skeletal growth. What is more, it has at least one huge enhydro (moving bubble in water) inside. Inside one of the sceptres are tiny red lepidocrocite crystals.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",311,{"id":557,"source_url":558,"license_code":322,"credit_html":559,"title":560,"description":561,"author":475,"original_width":562,"original_height":476},7847,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10160455","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10160455\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-209854.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSmoky_quartz\" class=\"extiw\" title=\"en:Smoky quartz\">Smoky Quartz\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 9.5 x 3.4 x 2.4 cm.\u003C\u002Fdd>\n\u003Cdd>This is a large, superb, and interesting Brandberg crystal. Most dramatic is the offset, parallel growth, with reverse sceptering. Add to this an easily visible enhydro (a moving bubble trapped inside a water pocket). And on top of all this, the clarity is magnificent, with a stunning mix of blushes of smoky and amethystine hues inside. Glassy luster, too. Ex. Richard Hauck Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",306,{"id":564,"source_url":565,"license_code":322,"credit_html":566,"title":567,"description":568,"author":475,"original_width":569,"original_height":500},7848,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10444815","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10444815\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-bb06a.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Goboboseb Mountains, Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-4534.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: small cabinet, 8.4 x 2.3 1.5 cm\n\u003Cdl>\u003Cdt>Quartz with Amethyst phantom and Enhydro\u003C\u002Fdt>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>Here you have a lovely quartz with wisps of amethyst and smoky AND a moveable water bubble embedded inside!\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",293,{"id":571,"source_url":572,"license_code":454,"credit_html":573,"title":574,"description":575,"author":576,"original_width":577,"original_height":578},10398,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=9720625","Michelle Jo, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=9720625\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Green Amethyst.JPG","Round cut green quartz gemstones.","Michelle Jo",3888,2592,{"id":580,"source_url":581,"license_code":322,"credit_html":582,"title":583,"description":584,"author":475,"original_width":585,"original_height":476},32594,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10138752","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10138752\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-114543.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Citrine\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Boekenhoutshoek area (Boekenhouthoek), Mkobola district, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FMpumalanga\" class=\"extiw\" title=\"en:Mpumalanga\">Mpumalanga Province\u003C\u002Fa>, South Africa (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-204011.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 7.8 x 7.2 x 4.2 cm.\u003C\u002Fdd>\n\u003Cdd>A cluster of amethyst crystals wrapped in sparkly orange citrine crystals, from Magaliesberg. The gemmy purple tips of the amethyst crystals providing a beautiful color contrast with the citrine below.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",516,{"id":587,"source_url":588,"license_code":312,"credit_html":589,"title":590,"description":591,"author":592,"original_width":593,"original_height":594},36970,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=47687442","Myself., via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=47687442\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Agate, amethyste, quartz.jpg","A slice of \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSillicate\" class=\"extiw\" title=\"w:Sillicate\">silicates\u003C\u002Fa> of my collection: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002Fagate\" class=\"extiw\" title=\"w:agate\">agate\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002Famethyst\" class=\"extiw\" title=\"w:amethyst\">amethyst\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002Fquartz\" class=\"extiw\" title=\"w:quartz\">quartz\u003C\u002Fa> from Baia-Sprie, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FMaramure%C8%99\" class=\"extiw\" title=\"w:Maramureș\">Maramureș\u003C\u002Fa>","Myself.",3207,3806,{"id":596,"source_url":597,"license_code":411,"credit_html":598,"title":599,"description":600,"author":601,"original_width":602,"original_height":603},37708,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84716762","Stephanie Clifford from Arlington, VA, USA, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84716762\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst, Cactus Quartz Variety, Mpumalanga, South Africa (3561494954).jpg","Amethyst, Cactus Quartz Variety, Mpumalanga, South Africa","Stephanie Clifford from Arlington, VA, USA",1102,1152,{"id":605,"source_url":606,"license_code":411,"credit_html":607,"title":608,"description":600,"author":601,"original_width":609,"original_height":610},37709,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84716764","Stephanie Clifford from Arlington, VA, USA, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84716764\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst, Cactus Quartz Variety, Mpumalanga, South Africa (3561494604).jpg",1046,775,{"id":612,"source_url":613,"license_code":312,"credit_html":614,"title":615,"description":616,"author":617,"original_width":618,"original_height":619},39148,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=187418235","Feedmepaperr, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=187418235\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst on blue chalcedony.jpg","Amethyst on blue chalcedony, with a white background","Feedmepaperr",2855,2856,{"id":621,"source_url":622,"license_code":322,"credit_html":623,"title":624,"description":625,"author":507,"original_width":460,"original_height":459},49400,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6187274","Parent Géry, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=6187274\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Citrine sur améthyste 1(République d'Afrique du Sud).jpg","quartz var. amethyst, quartz var. citrine : Karibib District, Erongo Region, Namibia",{"id":627,"source_url":628,"license_code":411,"credit_html":629,"title":630,"description":631,"author":415,"original_width":632,"original_height":633},57315,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622797","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622797\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 1 (31500046668).jpg","\u003Cp>\"Grape agate\" - amethyst & purple chalcedony from the Tertiary of Indonesia.\n\u003C\u002Fp>\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.  At its simplest, a mineral is a naturally-occurring solid chemical.  Currently, there are about 5400 named and described minerals - about 200 of them are common and about 20 of them are very common.  Mineral classification is based on anion chemistry.  Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.\n\u003C\u002Fp>\u003Cp>The silicates are the most abundant and chemically complex group of minerals.  All silicates have silica as the basis for their chemistry.  \"Silica\" refers to SiO2 chemistry.  The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4.  Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens \"belong\" to each silicon.  The resulting formula for silica is thus SiO2, not SiO4.\n\u003C\u002Fp>\u003Cp>The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2).  All other silicates have silica + impurities.  Many silicates have a significant percentage of aluminum (the aluminosilicates).\n\u003C\u002Fp>\u003Cp>Quartz (silicon dioxide\u002Fsilica - SiO2) is the most common mineral in the Earth's crust.  It is composed of the two most abundant elements in the crust - oxygen and silicon.  It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture.  Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc.\n\u003C\u002Fp>\u003Cp>Purple quartz is called amethyst.  The coloring agent for amethyst is not agreed upon.  Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn.\n\u003C\u002Fp>\u003Cp>This cluster of purplish rounded masses is a sample of \"grape agate\" or \"grape chalcedony\".  In reality, it's finely crystalline amethyst, although analysis has shown that purple chalcedony is also present.\n\u003C\u002Fp>\u003Cp>This material appears to be hydrothermal in origin and occurs along the altered\u002Fdegraded margins of Miocene-aged, porphyritic trachyandesite pillow lavas.\n\u003C\u002Fp>\u003Cp>Locality: mine in the mountains of the Mamuju area, West Sulawesi Province, Sulawesi, Indonesia\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo gallery of quartz and amethyst and grape agate:\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"http:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=3337\">http:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=3337\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=3337<\u002Fa>\nand\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=198\">https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=198\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=198<\u002Fa>\nand\n\u003C\u002Fp>\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=51479\">https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=51479\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=51479<\u002Fa>",1347,1340,{"id":635,"source_url":636,"license_code":411,"credit_html":637,"title":638,"description":631,"author":415,"original_width":639,"original_height":640},57316,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622800","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622800\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 2 (44651309754).jpg",2030,1475,{"id":642,"source_url":643,"license_code":411,"credit_html":644,"title":645,"description":631,"author":415,"original_width":646,"original_height":647},57317,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622801","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622801\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 3 (30435503407).jpg",2501,1572,{"id":649,"source_url":650,"license_code":411,"credit_html":651,"title":652,"description":653,"author":415,"original_width":654,"original_height":655},57318,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622803","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=84622803\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 4 (31500053438).jpg","\u003Cp>\"Grape agate\" - amethyst & purple chalcedony from the Tertiary of Indonesia.\n\u003C\u002Fp>\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.  At its simplest, a mineral is a naturally-occurring solid chemical.  Currently, there are about 5400 named and described minerals - about 200 of them are common and about 20 of them are very common.  Mineral classification is based on anion chemistry.  Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.\n\u003C\u002Fp>\u003Cp>The silicates are the most abundant and chemically complex group of minerals.  All silicates have silica as the basis for their chemistry.  \"Silica\" refers to SiO2 chemistry.  The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4.  Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens \"belong\" to each silicon.  The resulting formula for silica is thus SiO2, not SiO4.\n\u003C\u002Fp>\u003Cp>The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2).  All other silicates have silica + impurities.  Many silicates have a significant percentage of aluminum (the aluminosilicates).\n\u003C\u002Fp>\u003Cp>Quartz (silicon dioxide\u002Fsilica - SiO2) is the most common mineral in the Earth's crust.  It is composed of the two most abundant elements in the crust - oxygen and silicon.  It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture.  Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc.\n\u003C\u002Fp>\u003Cp>Purple quartz is called amethyst.  The coloring agent for amethyst is not agreed upon.  Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn.\n\u003C\u002Fp>\u003Cp>This cluster of purplish rounded masses is a sample of \"grape agate\" or \"grape chalcedony\" in matrix.  In reality, it's finely crystalline amethyst, although analysis has shown that purple chalcedony is also present.\n\u003C\u002Fp>\u003Cp>This material appears to be hydrothermal in origin and occurs along the altered\u002Fdegraded margins of Miocene-aged, porphyritic trachyandesite pillow lavas.\n\u003C\u002Fp>\u003Cp>Locality: mine in the mountains of the Mamuju area, West Sulawesi Province, Sulawesi, Indonesia\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo gallery of quartz and amethyst and grape agate:\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"http:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=3337\">http:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=3337\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=3337<\u002Fa>\nand\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=198\">https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=198\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=198<\u002Fa>\nand\n\u003C\u002Fp>\n<a href=\"\u003Ca rel=\"nofollow\" class=\"external free\" href=\"https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=51479\">https:\u002F\u002Fwww.mindat.org\u002Fgallery.php?min=51479\u003C\u002Fa>\" rel=\"nofollow\">www.mindat.org\u002Fgallery.php?min=51479<\u002Fa>",2657,1750,{"id":657,"source_url":658,"license_code":411,"credit_html":659,"title":660,"description":661,"author":415,"original_width":662,"original_height":508},57320,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=93640520","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=93640520\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 6.jpg","\"Grape agate\" - amethyst & purple chalcedony from the Tertiary of Indonesia. (~9.0 centimeters across at its widest)\n\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.  At its simplest, a mineral is a naturally-occurring solid chemical.  Currently, there are over 5600 named and described minerals - about 200 of them are common and about 20 of them are very common.  Mineral classification is based on anion chemistry.  Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.\n\u003C\u002Fp>\u003Cp>The silicates are the most abundant and chemically complex group of minerals.  All silicates have silica as the basis for their chemistry.  \"Silica\" refers to SiO2 chemistry.  The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4.  Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens \"belong\" to each silicon.  The resulting formula for silica is thus SiO2, not SiO4.\n\u003C\u002Fp>\u003Cp>The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2).  All other silicates have silica + impurities.  Many silicates have a significant percentage of aluminum (the aluminosilicates).\n\u003C\u002Fp>\u003Cp>Quartz (silicon dioxide\u002Fsilica - SiO2) is the most common mineral in the Earth's crust.  It is composed of the two most abundant elements in the crust - oxygen and silicon.  It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture.  Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc.\n\u003C\u002Fp>\u003Cp>Purple quartz is called amethyst.  The coloring agent for amethyst is not agreed upon.  Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn.\n\u003C\u002Fp>\u003Cp>This cluster of purplish rounded masses is a sample of \"grape agate\" or \"grape chalcedony\".  In reality, it's finely crystalline amethyst, although analysis has shown that purple chalcedony is also present.\n\u003C\u002Fp>\u003Cp>This material appears to be hydrothermal in origin and occurs along the altered\u002Fdegraded margins of Miocene-aged, porphyritic trachyandesite pillow lavas.\n\u003C\u002Fp>\u003Cp>Locality: mine in the mountains of the Mamuju area, West Sulawesi Province, Sulawesi, Indonesia\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo gallery of quartz and amethyst and grape agate:\nwww.mindat.org\u002Fgallery.php?min=3337\nand\nwww.mindat.org\u002Fgallery.php?min=198\nand\n\u003C\u002Fp>\nwww.mindat.org\u002Fgallery.php?min=51479",3522,{"id":664,"source_url":665,"license_code":411,"credit_html":666,"title":667,"description":668,"author":415,"original_width":669,"original_height":670},57321,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=93640522","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=93640522\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Amethyst & purple chalcedony (Tertiary; Sulawesi, Indonesia) 5.jpg","\"Grape agate\" - amethyst & purple chalcedony from the Tertiary of Indonesia. (~9.0 centimeters across at its widest)\n\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties.  At its simplest, a mineral is a naturally-occurring solid chemical.  Currently, there are over 5500 named and described minerals - about 200 of them are common and about 20 of them are very common.  Mineral classification is based on anion chemistry.  Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.\n\u003C\u002Fp>\u003Cp>The silicates are the most abundant and chemically complex group of minerals.  All silicates have silica as the basis for their chemistry.  \"Silica\" refers to SiO2 chemistry.  The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4.  Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens \"belong\" to each silicon.  The resulting formula for silica is thus SiO2, not SiO4.\n\u003C\u002Fp>\u003Cp>The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2).  All other silicates have silica + impurities.  Many silicates have a significant percentage of aluminum (the aluminosilicates).\n\u003C\u002Fp>\u003Cp>Quartz (silicon dioxide\u002Fsilica - SiO2) is the most common mineral in the Earth's crust.  It is composed of the two most abundant elements in the crust - oxygen and silicon.  It has a glassy, nonmetallic luster, is commonly clearish to whitish to grayish in color, has a white streak, is quite hard (H≡7), forms hexagonal crystals, has no cleavage, and has conchoidal fracture.  Quartz can be any color: clear, white, gray, black, brown, pink, red, purple, blue, green, orange, etc.\n\u003C\u002Fp>\u003Cp>Purple quartz is called amethyst.  The coloring agent for amethyst is not agreed upon.  Some workers say that it is due to Fe+4 impurity, some say the impurity is Fe+3, and others say it is Mn.\n\u003C\u002Fp>\u003Cp>This cluster of purplish rounded masses is a sample of \"grape agate\" or \"grape chalcedony\".  In reality, it's finely crystalline amethyst, although analysis has shown that purple chalcedony is also present.\n\u003C\u002Fp>\u003Cp>This material appears to be hydrothermal in origin and occurs along the altered\u002Fdegraded margins of Miocene-aged, porphyritic trachyandesite pillow lavas.\n\u003C\u002Fp>\u003Cp>Locality: mine in the mountains of the Mamuju area, West Sulawesi Province, Sulawesi, Indonesia\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo gallery of quartz and amethyst and grape agate:\nwww.mindat.org\u002Fgallery.php?min=3337\nand\nwww.mindat.org\u002Fgallery.php?min=198\nand\n\u003C\u002Fp>\nwww.mindat.org\u002Fgallery.php?min=51479",3253,2394,{"id":672,"source_url":673,"license_code":322,"credit_html":674,"title":675,"description":676,"author":475,"original_width":677,"original_height":476},64297,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10138489","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10138489\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-112901.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 5.3 x 4.5 x 3.5 cm.\u003C\u002Fdd>\n\u003Cdd>Another Brandberg amethyst, this one of a completely different style, and on MATRIX. It shows slight sceptering as well as skeletal growth at the top. There is actually a phantom inside, with the inner crystal being more colorless, outlined by the purple of the crystal that enveloped it. The crystal also features very prominent microcrystals of red lepidocrocite. Ex. Charlie Key collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",395,{"id":679,"source_url":680,"license_code":322,"credit_html":681,"title":682,"description":683,"author":475,"original_width":684,"original_height":476},64298,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10140525","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10140525\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-121242.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 6.3 x 3.0 x 2.5 cm.\u003C\u002Fdd>\n\u003Cdd>A spectacular example, even better in person, of pristine, intensely bright and gemmy amethyst from Brandberg - like no other amethyst in the world. It has these wonderful subtle blushes of purple inside, and you can even see little bright red crystals of lepidocrocite included inside! There are three crystals here growing in parallel.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",313,{"id":686,"source_url":687,"license_code":322,"credit_html":688,"title":689,"description":690,"author":475,"original_width":691,"original_height":476},78391,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162411","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10162411\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-222377.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSmoky_quartz\" class=\"extiw\" title=\"en:Smoky quartz\">Smoky Quartz\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>)\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Goboboseb Mountains, Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-4534.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 4.4 x 1.4 x 1.3 cm.\u003C\u002Fdd>\n\u003Cdd>A fine sceptered smoky\u002Famethyst quartz specimen from the Goboboseb Mountains of Namibia, The intensely purple and glassy amethyst shaft has gemmy, smoky quartz scepters on both ends. The two, staggered scepters are beautiful and some faces have skeletal features. The amethyst shaft is broken and healed on the other end and one side of the smoky scepter is contacted. Ex. Rob Smith Collection.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",427,{"id":693,"source_url":694,"license_code":322,"credit_html":695,"title":696,"description":697,"author":475,"original_width":698,"original_height":699},78392,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10171254","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10171254\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-Tourmaline-273111.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FSmoky_quartz\" class=\"extiw\" title=\"en:Smoky quartz\">Smoky Quartz\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa> (Var.: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAmethyst\" class=\"extiw\" title=\"en:Amethyst\">Amethyst\u003C\u002Fa>), \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FTourmaline\" class=\"extiw\" title=\"en:Tourmaline\">Tourmaline\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-46238.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: 6.8 x 2.2 x 1.8 cm.\u003C\u002Fdd>\n\u003Cdd>A beautiful single crystal of light Smoky Quartz, terminating in a sharp Amethyst reverse scepter. The crystal is gemmy throughout. The Smoky portion has striated, slightly frosted faces while the scepter has superb luster. There are also many fine Tourmaline needle inclusions in the Amethyst tip. A very aesthetic, and not very common, specimen. Ex. Charlie Key.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",248,500,{"id":701,"source_url":702,"license_code":322,"credit_html":703,"title":704,"description":705,"author":475,"original_width":706,"original_height":500},78394,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10444867","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10444867\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-bb124a.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Goboboseb Mountains, Brandberg area, Brandberg District, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FErongo_Region\" class=\"extiw\" title=\"en:Erongo Region\">Erongo Region\u003C\u002Fa>, Namibia (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-4534.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Size: cabinet, 14.6 x 11.6 x 7.3 cm\n\u003Cdl>\u003Cdt>Smoky Quartz (sceptred and hoppered)\u003C\u002Fdt>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>A dramatic, complex, massive smoky quartz with glassy luster and a hint of amethyst on select faces of . This monster shows skeletal and hopper growth, and is much more dramatic in person. It is very 3-dimensional and complete all around!\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",617,{"id":708,"source_url":709,"license_code":322,"credit_html":710,"title":711,"description":712,"author":475,"original_width":485,"original_height":713},78397,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10446021","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10446021\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-ckorqtz-51c.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Oranje River, Namibia\u003C\u002Fdd>\n\u003Cdd>Size: small cabinet, 9.8 x 6.9 x 4.4 cm\n\u003Cdl>\u003Cdt>Quartz\u003C\u002Fdt>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>This \"floater\" quartz specimen has a lot going for it. It is a complete, doubly-terminated floater (complete front and back!), with no visible points of attachment, the largest crystal is 7.0 cm in length, and it is sceptered. All the crystals are glassy, gemmy, with both amethyst and a rich reddish-brown caused by hematite inclusions. Front and back are shown in the top panel of photos. In addition, the second largest crystal has a distinct phantom right at the termination. Exciting and amazing!\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",397,{"id":715,"source_url":716,"license_code":322,"credit_html":717,"title":718,"description":719,"author":475,"original_width":720,"original_height":485},78400,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10446068","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10446068\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Quartz-ckorqtz-71b.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FQuartz\" class=\"extiw\" title=\"en:Quartz\">Quartz\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: Oranje River, Namibia\u003C\u002Fdd>\n\u003Cdd>Size: miniature, 5.7 x 1.9 x 1.6 cm\n\u003Cdl>\u003Cdt>Quartz\u003C\u002Fdt>\u003C\u002Fdl>\u003C\u002Fdd>\n\u003Cdd>The stem of this sceptered quartz crystal, which was originally colorless, now has a dusting of rose colored hematite. This contrasts nicely with the glassy and gemmy termination which exhibits a purple, amethyst color center.\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>",288,[],[723,724,725,726,727,728,729,730,731,732,733,734,735,736,737,738,739,740,741,742,743,744,745,746],"Aimitis","Amatista","Ametėsts","Amethist","Améthyste","Amethystine Agate","Amethystine quartz","Amethystus","Ametist","Ametista","Ametistas","Ametisti","Ametisto","Ametists","Ametiszt","Ametüst","Ametyst","Bacchusstein","Bishops Stone","Black Amethyst","Haaramethyst","Lavendine","Tlapaltehuilōtl","Αμέθυστος",[],{"history":749,"applications":754},{"markdown":750,"model_version":751,"prompt_version":752,"reviewed_at":753},"The name **amethyst** comes from the greek *amethystos* — literally *not drunk*[1]. The ancient Greeks took the meaning at its word. Drinking cups were sometimes carved from amethyst, and the red wine poured into them was said to look about the same colour as the cup itself[2]. The wine could then be quietly diluted with water without the drinker noticing — the stone, not the dilution, was credited with keeping the room sober.\n\nThe Egyptians worked the mineral long before Europe attached stories to it. They cut amethyst as a gemstone and used it for intaglio engraved gems — small designs cut into the stone's surface, usually for sealing wax[3]. The stone reached Rome along the same gem trade: a carved portrait of the emperor Caracalla in amethyst survived for centuries in the Treasury of Sainte-Chapelle[4].\\\nThe first-century Roman naturalist Pliny the Elder, in his *Natural History*, was unconvinced by the protective claim. He wrote that *the falsehoods of the magicians would persuade us that these stones are preventive of inebriety, and that it is from this that they have derived their name*[5].\n\nReligious tradition picked up the stone in two distinct threads. The Hebrew Bible places it on the breastplate of the high priest: amethyst appears in Exodus 28:19 and 39:12 as one of the twelve stones set in the *ḥoshen*, the breastplate of judgement[6]. The Hebrew name *aḥlamah* is rendered as *amethystos* in the Septuagint — the Greek translation of the Hebrew scriptures — fixing the modern identification of the stone[7].\\\nThe Christian thread runs through the New Testament. Acts 2:15 records Peter telling the crowd at Pentecost that the apostles are *not drunk* — a phrase that echoes the Greek meaning of the stone's name almost exactly. Anglican bishops still wear an episcopal ring often set with an amethyst as a direct allusion to that verse[8].\n\nIn the Middle Ages the stone widened its symbolic range. European soldiers wore amethyst amulets into battle, believing the stone could heal them and keep them cool-headed[9]. It was treated as a symbol of royalty and used to decorate the English regalia — the crowns, sceptres and other ornaments of the monarchy[10]. Tibetan Buddhists, on the other side of the trade routes, took it as sacred to the Buddha and made prayer beads from it[11].\n\nThe myth that anchored the *amethystos* name to a face came much later than the etymology itself. The French Renaissance poet Rémy Belleau (1528–1577) wrote a poem in which Bacchus pursued a maiden named Amethyste, who refused his affections — a literary invention later mistaken for ancient lore[12].\n\nUntil the 18th century, amethyst sat among the **cardinal gems** — the most valuable stones in the European tradition, alongside diamond, sapphire, ruby and emerald[13]. That standing collapsed when extensive deposits were found in Brazil. A large geode from near Santa Cruz in southern Brazil was shipped across the Atlantic and presented at a 1902 exhibition in Düsseldorf, Germany[14]. With supply now measured in tonnes rather than rare finds, amethyst lost most of its value and dropped out of that top rank.","claude-opus-4-7","1.7.0","2026-06-02 15:16:04",{"markdown":755,"model_version":751,"prompt_version":752,"reviewed_at":756},"Amethyst's only significant modern role is as a **gemstone and ornamental material**. The violet stone is faceted and set in jewellery as a semiprecious gem, typically in prong or bezel settings; channel settings are used with caution[1]. Collectors and cutters prize specimens that show depth of colour and the red flashes that appear when light catches a well-cut crystal[1]. Amethyst is the traditional birthstone of February, which gives the trade a built-in market for rings, pendants and earrings throughout the year[2].\n\nBeyond cut stones, the trade in **amethyst geodes** — hollow rock cavities lined with crystals — is brisk. The hollow agates of southwestern Brazil and Uruguay regularly contain a crop of amethyst crystals on their inner walls[3], and the larger specimens travel from mine to gem show as polished display pieces. One geode at the American Museum of Natural History stands 3.7 metres tall and weighs four tonnes[4]. Mineral collectors are the other half of this trade — single crystals, clusters and small geodes circulate continuously between dealers, fairs and private cabinets.\n\nCommercial supply today rests on a few countries. Between 2000 and 2010, the largest production came from Marabá and Pau d'Arco in Pará, and the Paraná Basin in Rio Grande do Sul, both in Brazil[5]. Zambia is the other major producer, with an annual output around 1000 tonnes[6].\n\nSome commercial citrine — the yellow variety of quartz — is not natural at all but **heat-treated amethyst**. Exposure to heat cancels the irradiation effects that give amethyst its purple colour, leaving the crystal yellow or sometimes green. Much of the citrine, cairngorm and other yellow quartz on the jewellery market is, in the trade's own phrase, *burnt amethyst*[7].\n\nSynthetic amethyst competes with the natural stone on the lower end of the gem market. It is grown by **hydrothermal growth** — silica feedstock dissolved in a hot alkaline solution inside a high-pressure autoclave, then crystallised onto a seed[8]. The technique was first scaled commercially for clear quartz at Bell Laboratories in 1950, in response to a wartime shortage of natural Brazilian crystals for the electronics industry[9]. Coloured varieties followed. Synthetic amethyst has the same chemistry and physical properties as the natural stone, but the specific twinning patterns found in natural specimens are absent[8]. That absence is the main diagnostic for telling the two apart.","2026-06-02 15:24:22"]