[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"minerals:one:3449":3},{"id":4,"longid":5,"guid":6,"name":7,"shortcode_ima":8,"entrytype":9,"entrytype_text":10,"varietyof":11,"synid":11,"polytypeof":11,"groupid":12,"weighting":13,"nolocadd":14,"blacklisted":14,"mindat_formula":15,"mindat_formula_note":11,"ima_formula":16,"elements":17,"sigelements":24,"key_elements":25,"impurities":26,"cim":27,"ima_status":28,"ima_notes":11,"ima_history":11,"approval_year":11,"publication_year":31,"discovery_year":32,"strunz10ed1":33,"strunz10ed2":34,"strunz10ed3":35,"strunz10ed4":36,"dana8ed1":37,"dana8ed2":38,"dana8ed3":39,"dana8ed4":40,"csystem":41,"cclass":42,"spacegroup":43,"spacegroupset":44,"a":45,"b":46,"c":47,"alpha":48,"beta":49,"gamma":48,"aerror":11,"berror":11,"cerror":11,"alphaerror":11,"betaerror":11,"gammaerror":11,"va3":11,"z":50,"csmetamict":14,"commentcrystal":11,"twinning":11,"tranglide":11,"parting":11,"epitaxidescription":11,"morphology":51,"tlform":52,"hmin":53,"hmax":53,"hardtype":11,"vhnmin":48,"vhnmax":48,"vhnerror":11,"vhng":11,"vhns":11,"commenthard":11,"dmeas":54,"dmeas2":55,"dcalc":56,"dmeaserror":11,"dcalcerror":11,"commentdense":11,"lustre":11,"lustretype":57,"commentluster":11,"diapheny":58,"streak":59,"colour":60,"commentcolor":11,"colors":61,"streak_colors":66,"luminescence":11,"uv":11,"cleavage":67,"cleavagetype":68,"fracturetype":11,"tenacity":11,"commentbreak":11,"opticaltype":69,"opticalsign":70,"opticalalpha":71,"opticalalpha2":72,"opticalalphaerror":11,"opticalbeta":73,"opticalbeta2":74,"opticalbetaerror":11,"opticalgamma":75,"opticalgamma2":76,"opticalgammaerror":11,"opticalomega":48,"opticalomega2":48,"opticalomegaerror":11,"opticalepsilon":48,"opticalepsilon2":48,"opticalepsilonerror":11,"opticaln":48,"opticaln2":48,"opticalnerror":11,"optical2vcalc":48,"optical2vcalc2":48,"optical2vcalcerror":11,"optical2vmeasured":77,"optical2vmeasured2":78,"optical2vmeasurederror":11,"rimin":79,"rimax":80,"opticaldispersion":81,"opticalpleochroism":82,"opticalpleochorismdesc":83,"opticalbirefringence":11,"opticalcomments":11,"opticalcolour":11,"opticalinternal":11,"opticaltropic":11,"opticalanisotropism":11,"opticalbireflectance":11,"opticalextinction":11,"opticalr":11,"specdispm":11,"ir":11,"electrical":11,"magnetism":11,"thermalbehaviour":84,"other":85,"industrial":11,"occurrence":86,"otheroccurrence":87,"type_specimen_store":88,"description_short":89,"aboutname":90,"rock_parent":11,"rock_parent2":11,"rock_root":9,"rock_bgs_code":11,"meteoritical_code":11,"updttime":91,"reviewed_at":11,"variety_of":11,"varieties":92,"group_members":93,"associates":140,"confused_with":151,"type_localities":152,"occurrence_total":159,"citations":160,"images":241,"structures":271,"synonyms":272,"language_names":276,"wikidata_qid":321,"texts":322},3449,"1:1:3449:0","216f9772-0f9d-4766-9b83-b16923a5a72f","Roscoelite","Rcl",0,"mineral",null,53391,507,false,"KV\u003Csup>3+\u003C\u002Fsup>\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>","KV\u003Csup>3+\u003C\u002Fsup>\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>Al)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>",[18,19,20,21,22,23],"Al","Si","O","K","H","V",[18,19,20,21,22,23],[23],",Fe,Ca,Na,H2O,","16.15.1",[29,30],"APPROVED","GRANDFATHERED",1876,"1876","9","E","C","15","71","2","2a","4","Monoclinic",5,10,"C2\u002Fc ","5.26","9.09","10.25","0","101",2,"Minute scales, druses, rosettes, fan shaped groups, fibrous, felted aggregates, impregnations, massive.","Radiating and foliated talc-like masses.",2.5,"2.92","2.94","2.89","Pearly","Transparent,Translucent","Gray","Brown, dark green to black",[62,63,64,65],"green","black","brown","gray",[65],"on {001}","Perfect","Biaxial","-","1.59","1.610","1.63","1.685","1.64","1.704","24.5","39.5",1.59,1.704,"r \u003C v weak","Visible","X = green-brown; Y = Z = olive-green.","Before the blowpipe, it fuses easily to a black glass, coloring the flame slightly pink.","Only slightly affected by acids, even by boiling concentrated sulphuric acid. But readily decomposed by dilute sulphuric acid when heated in a sealed tube at a temperature of about 180°C.","Filling cavities in a schistose porphyry.","Low temperature epithermal Au-Ag-Te deposits and oxidized portions of sedimentary U-V deposits.","Muséum Nationale d’Histoire Naturelle, Paris, France, number 132.198 (type).","Mica Group.\r\nThe V(III) analogue of muscovite with which it forms a solid-solution series.","For Sir Henry Enfield Roscoe, FRS (7 January 1833 - 18 December 1915), an English chemist particularly noted for early work on vanadium and for photochemical studies.","2025-09-23 16:14:20",[],[94,102,108,116,124,132],{"id":95,"name":96,"entrytype":9,"csystem":41,"ima_formula":97,"mindat_formula":98,"hmin":53,"hmax":99,"dmeas":100,"dcalc":56,"primary_image_id":101},729,"Boromuscovite","KAl\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>B)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>","KAl\u003Csub>2\u003C\u002Fsub>(BSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>",3,"2.81",3672,{"id":103,"name":104,"entrytype":9,"csystem":41,"ima_formula":105,"mindat_formula":105,"hmin":99,"hmax":99,"dmeas":106,"dcalc":107,"primary_image_id":11},6872,"Chromphyllite","KCr\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>","2.88","2.86",{"id":109,"name":110,"entrytype":9,"csystem":41,"ima_formula":111,"mindat_formula":112,"hmin":53,"hmax":53,"dmeas":113,"dcalc":114,"primary_image_id":115},2815,"Muscovite","KAl\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>Al)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>","KAl\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>","2.77","2.83",30243,{"id":117,"name":118,"entrytype":9,"csystem":41,"ima_formula":119,"mindat_formula":120,"hmin":50,"hmax":99,"dmeas":121,"dcalc":122,"primary_image_id":123},2839,"Nanpingite","CsAl\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>Al)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>","CsAl\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH,F)\u003Csub>2\u003C\u002Fsub>","3.11","3.19",17013,{"id":125,"name":126,"entrytype":9,"csystem":41,"ima_formula":127,"mindat_formula":128,"hmin":53,"hmax":99,"dmeas":129,"dcalc":130,"primary_image_id":131},3090,"Paragonite","NaAl\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>Al)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>","NaAl\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>","2.85","2.907",30412,{"id":133,"name":134,"entrytype":9,"csystem":41,"ima_formula":135,"mindat_formula":136,"hmin":50,"hmax":50,"dmeas":137,"dcalc":138,"primary_image_id":139},3984,"Tobelite","(NH\u003Csub>4\u003C\u002Fsub>)Al\u003Csub>2\u003C\u002Fsub>(Si\u003Csub>3\u003C\u002Fsub>Al)O\u003Csub>10\u003C\u002Fsub>(OH)\u003Csub>2\u003C\u002Fsub>","(NH\u003Csub>4\u003C\u002Fsub>)Al\u003Csub>2\u003C\u002Fsub>(AlSi\u003Csub>3\u003C\u002Fsub>O\u003Csub>10\u003C\u002Fsub>)(OH)\u003Csub>2\u003C\u002Fsub>","2.58","2.617",24300,[141],{"id":142,"name":143,"entrytype":9,"csystem":144,"ima_formula":145,"mindat_formula":146,"hmin":147,"hmax":148,"dmeas":149,"dcalc":150,"primary_image_id":11},3835,"Suzukiite","Orthorhombic","BaV\u003Csup>4+\u003C\u002Fsup>Si\u003Csub>2\u003C\u002Fsub>O\u003Csub>7\u003C\u002Fsub>","BaVSi\u003Csub>2\u003C\u002Fsub>O\u003Csub>7\u003C\u002Fsub>",4,4.5,"4.0","4.03",[],[153],{"id":154,"txt":155,"latitude":156,"longitude":157,"country":158},8135,"Stuckslager Mine (Stuckslacker Mine; Sam Simms Mine), Coloma, Coloma Mining District, West Belt, El Dorado County, California, USA",38.7855556,-120.9172222,"USA",220,[161,165,168,171,174,179,184,189,192,196,200,204,209,214,219,223,227,232,236],{"id":162,"year":163,"html":164,"doi":11},16122152,1875,"Blake, J. (1875). Roscoelite, a vanadium mica. California Academy of Science Proceedings, 6, 150-151.",{"id":166,"year":31,"html":167,"doi":11},15965999,"Genth, F.A. (1876) On some American vanadium minerals: American Journal of Science, 3rd. series: 12: 32-36",{"id":169,"year":31,"html":170,"doi":11},16122153,"Blake, James (1876). Roscoelite, a vanadium mica. Scientific American Supplement, 35, 553-553.",{"id":172,"year":31,"html":173,"doi":11},16122154,"Blake, J. (1876). On roscolite, a vanadium mica. American Journal of Science, 3rd. series, 12, 31-32.",{"id":175,"year":176,"html":177,"doi":178},2611622,1877,"Roscoe, H. E. (1877) IV. On two new vanadium minerals. \u003Ci>Proceedings of the Royal Society of London\u003C\u002Fi>, 25 (171) 109-112 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1098\u002Frspl.1876.0023'>doi:10.1098\u002Frspl.1876.0023\u003C\u002Fa>","10.1098\u002Frspl.1876.0023",{"id":180,"year":181,"html":182,"doi":183},398949,1878,"Des Cloizeaux, Alfred (1878) Sur la Roscoelite. \u003Ci>Bulletin de Minéralogie\u003C\u002Fi>,  1 (3) 51 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.3406\u002Fbulmi.1878.1411'>doi:10.3406\u002Fbulmi.1878.1411\u003C\u002Fa>","10.3406\u002Fbulmi.1878.1411",{"id":185,"year":186,"html":187,"doi":188},399113,1881,"Des Cloizeaux, Alfred (1881) Sur la Roscoelite, la karyinite et la monazite. \u003Ci>Bulletin de Minéralogie\u003C\u002Fi>,  4 (3) 56-58 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.3406\u002Fbulmi.1881.1627'>doi:10.3406\u002Fbulmi.1881.1627\u003C\u002Fa>","10.3406\u002Fbulmi.1881.1627",{"id":190,"year":186,"html":191,"doi":11},16122156,"Hanks, H.G. (1881) Notes on roscoelite. Mining and Scientific Press: 42: 428.",{"id":193,"year":194,"html":195,"doi":11},15966001,1899,"Hillebrand, W.F, Turner, H.W., and Clarke, F.W. (1899) On roscoelite, with a note on its chemical composition. American Journal of Science, 4th. series: 7: 456.",{"id":197,"year":198,"html":199,"doi":11},15966002,1900,"Hillebrand, W.F. (1900) Mineralogical notes: SS Bulletin 167: 70.",{"id":201,"year":202,"html":203,"doi":11},16122160,1914,"Wright, F.E. (1914) The optical properties of roscoelite. American Journal of Science, 4th. series: 38: 305-308.",{"id":205,"year":206,"html":207,"doi":208},1155536,1955,"Heinrich, E. W., Levinson, A. A. (1955) Studies in the mica group; x-ray data on roscoelite and barium-muscovite. \u003Ci>American Journal of Science\u003C\u002Fi>,  253 (1) 39-43 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.2475\u002Fajs.253.1.39'>doi:10.2475\u002Fajs.253.1.39\u003C\u002Fa>","10.2475\u002Fajs.253.1.39",{"id":210,"year":211,"html":212,"doi":213},81377,1965,"ITO, JUN (1965) Synthesis of vanadium silicates: haradaite, goldmanite and roscoelite. \u003Ci>Mineralogical Journal\u003C\u002Fi>,  4 (4). 299-316 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.2465\u002Fminerj1953.4.299'>doi:10.2465\u002Fminerj1953.4.299\u003C\u002Fa> \u003Ca target='_blank' href='https:\u002F\u002Fwww.jstage.jst.go.jp\u002Farticle\u002Fminerj1953\u002F4\u002F4\u002F4_4_299\u002F_pdf' class='refpdflink'>\u003C\u002Fa>","10.2465\u002Fminerj1953.4.299",{"id":215,"year":216,"html":217,"doi":218},89435,1990,"MATSUBARA, SATOSHI, SAITO, YASUJI, KATO, AKIRA (1990) Vanadium minerals in siliceous sedimentary rocks from Unuma, Gifu Prefecture, Japan, with special reference to volborthite and roscoelite. \u003Ci>Journal of Mineralogy, Petrology and Economic Geology\u003C\u002Fi>,  85 (11) 522-530 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.2465\u002Fganko.85.522'>doi:10.2465\u002Fganko.85.522\u003C\u002Fa> \u003Ca target='_blank' href='https:\u002F\u002Fwww.jstage.jst.go.jp\u002Farticle\u002Fganko1988\u002F85\u002F11\u002F85_11_522\u002F_pdf' class='refpdflink'>\u003C\u002Fa>","10.2465\u002Fganko.85.522",{"id":220,"year":221,"html":222,"doi":11},15949274,1998,"Rieder, M., Cavazzini, G., D’Yakonov, Y.S., Frank-Kamenetskii, V.A., Gottardt, G., Guggenheim, S., Koval, P.V., Muller, G., Neiva, A.M.R., Radoslovich, E.W., Robert, J.L., Sassi, F.P., Takeda, H., Weiss, Z., Wones, D.R. (1998) Nomenclature of the micas. \u003Ci>The Canadian Mineralogist\u003C\u002Fi>,  36 (3) 905-912 \u003Ca target='_blank' href='https:\u002F\u002Frruff.info\u002Fuploads\u002FCM36_905.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":224,"year":225,"html":226,"doi":11},16967046,2001,"(2001) Roscoelite. \u003Ci>Handbook of Mineralogy\u003C\u002Fi>. Mineralogical Society of America \u003Ca target='_blank' href='https:\u002F\u002Fwww.handbookofmineralogy.org\u002Fpdfs\u002Froscoelite.pdf' class='refpdflink'>\u003C\u002Fa>",{"id":228,"year":229,"html":230,"doi":231},147813,2003,"Brigatti, Maria Franca, Caprilli, Enrico, Marchesini, Marco, Poppi, Luciano (2003) The crystal structure of roscoelite-1\u003CI>M\u003C\u002FI>. \u003Ci>Clays and Clay Minerals\u003C\u002Fi>,  51 (3). 301-308 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1346\u002Fccmn.2003.0510306'>doi:10.1346\u002Fccmn.2003.0510306\u003C\u002Fa>","10.1346\u002Fccmn.2003.0510306",{"id":233,"year":234,"html":235,"doi":11},16338533,2010,"Hongzhou Zhu, Junfu Hou, and Shuli Wang (2010): Study on occurrence of vanadium in the Qianjiaping vanadium deposit of the South Qinling. Geology and Exploration 46(4), 643-648 (in Chinese with English abstract).",{"id":237,"year":238,"html":239,"doi":240},15784842,2023,"Zanetta, Pierre-Marie, Drexler, Maxwell S, Barton, Isabel F, Zega, Thomas J (2023) Vanadium Electronic Configuration Determination From L2,3 Transition in V-oxide Compounds and Roscoelite. \u003Ci>Microscopy and Microanalysis\u003C\u002Fi>, 29 (2) 459-469 \u003Ca target='_blank' href='https:\u002F\u002Fdoi.org\u002F10.1093\u002Fmicmic\u002Fozac057'>doi:10.1093\u002Fmicmic\u002Fozac057\u003C\u002Fa>","10.1093\u002Fmicmic\u002Fozac057",[242,249,253,263],{"id":243,"source_url":244,"license_code":245,"credit_html":246,"title":7,"description":11,"author":11,"original_width":247,"original_height":248},29451,"https:\u002F\u002Fgeocollections.info\u002Ffile\u002F179513","CC BY-SA 4.0","Photo: Unknown author — http:\u002F\u002Fcreativecommons.org\u002Flicenses\u002Fby-sa\u002F4.0\u002F, courtesy of \u003Ca href=\"https:\u002F\u002Fgeocollections.info\u002Ffile\u002F179513\" rel=\"noopener\">University of Tartu, Natural History Museum\u003C\u002Fa> via Europeana",1000,750,{"id":250,"source_url":251,"license_code":245,"credit_html":252,"title":7,"description":11,"author":11,"original_width":247,"original_height":248},29452,"https:\u002F\u002Fgeocollections.info\u002Ffile\u002F179515","Photo: Unknown author — http:\u002F\u002Fcreativecommons.org\u002Flicenses\u002Fby-sa\u002F4.0\u002F, courtesy of \u003Ca href=\"https:\u002F\u002Fgeocollections.info\u002Ffile\u002F179515\" rel=\"noopener\">University of Tartu, Natural History Museum\u003C\u002Fa> via Europeana",{"id":254,"source_url":255,"license_code":256,"credit_html":257,"title":258,"description":259,"author":260,"original_width":261,"original_height":262},21130,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=39952279","CC BY 2.0","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=39952279\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Gold & roscoelite (Stuckslacker Mine, Coloma, California, USA) (16562912783).jpg","\u003Cp>Gold and roscoelite from California, USA. (public display, Leadville Mining Museum, Leadville, Colorado, USA)\n\u003C\u002Fp>\u003Cp>A mineral is a naturally-occurring, solid, inorganic, crystalline substrance 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 4900 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>Elements are fundamental substances of matter - matter that is composed of the same types of atoms.  At present, 118 elements are known (four of them are still unnamed).  Of these, 98 occur naturally on Earth (hydrogen to californium).  Most of these occur in rocks & minerals, although some occur in very small, trace amounts.  Only some elements occur in their native elemental state as minerals.\n\u003C\u002Fp>\u003Cp>To find a native element in nature, it must be relatively non-reactive and there must be some concentration process.  Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state as minerals.\n\u003C\u002Fp>\u003Cp>Gold (Au) is the most prestigious metal known, but it's not the most valuable.  Gold is the only metal that has a deep, rich, metallic yellow color.  Almost all other metals are silvery-colored.  Gold is very rare in crustal rocks - it averages about 5 ppb (parts per billion).  Where gold has been concentrated, it occurs as wires, dendritic crystals, twisted sheets, octahedral crystals, and variably-shaped nuggets.  It most commonly occurs in hydrothermal quartz veins, disseminated in some contact- & hydrothermal-metamorphic rocks, and in placer deposits.  Placers are concentrations of heavy minerals in stream gravels or in cracks on bedrock-floored streams.  Gold has a high specific gravity (about 19), so it easily accumulates in placer deposits.  Its high density allows prospectors to readily collect placer gold by panning.\n\u003C\u002Fp>\u003Cp>In addition to its high density, gold has a high melting point (over 1000º C).  Gold is also relatively soft - about 2.5 to 3 on the Mohs Hardness Scale.  The use of pure gold or high-purity gold in jewelry is not desirable as it easily gets scratched.  The addition of other metals to gold to increase the hardness also alters the unique color of gold.  Gold jewelry made & sold in America doesn’t have the gorgeous rich color of high-purity gold.\n\u003C\u002Fp>\nLocality: Stuckslacker Mine, Coloma, California, USA","James St. John",1797,1108,{"id":264,"source_url":265,"license_code":256,"credit_html":266,"title":267,"description":268,"author":260,"original_width":269,"original_height":270},21131,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=87884948","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=87884948\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Gold & roscoelite (Stuckslacker Mine, Coloma, California, USA).jpg","Gold and roscoelite from California, USA. (public display, Leadville Mining Museum, Leadville, Colorado, 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 4900 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>Elements are fundamental substances of matter - matter that is composed of the same types of atoms.  At present, 118 elements are known (four of them are still unnamed).  Of these, 98 occur naturally on Earth (hydrogen to californium).  Most of these occur in rocks & minerals, although some occur in very small, trace amounts.  Only some elements occur in their native elemental state as minerals.\n\u003C\u002Fp>\u003Cp>To find a native element in nature, it must be relatively non-reactive and there must be some concentration process.  Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state as minerals.\n\u003C\u002Fp>\u003Cp>Gold (Au) is the most prestigious metal known, but it's not the most valuable.  Gold is the only metal that has a deep, rich, metallic yellow color.  Almost all other metals are silvery-colored.  Gold is very rare in crustal rocks - it averages about 5 ppb (parts per billion).  Where gold has been concentrated, it occurs as wires, dendritic crystals, twisted sheets, octahedral crystals, and variably-shaped nuggets.  It most commonly occurs in hydrothermal quartz veins, disseminated in some contact- & hydrothermal-metamorphic rocks, and in placer deposits.  Placers are concentrations of heavy minerals in stream gravels or in cracks on bedrock-floored streams.  Gold has a high specific gravity (about 19), so it easily accumulates in placer deposits.  Its high density allows prospectors to readily collect placer gold by panning.\n\u003C\u002Fp>\u003Cp>In addition to its high density, gold has a high melting point (over 1000º C).  Gold is also relatively soft - about 2.5 to 3 on the Mohs Hardness Scale.  The use of pure gold or high-purity gold in jewelry is not desirable as it easily gets scratched.  The addition of other metals to gold to increase the hardness also alters the unique color of gold.  Gold jewelry made & sold in America doesn’t have the gorgeous rich color of high-purity gold.\n\u003C\u002Fp>\u003Cp>Locality: Stuckslacker Mine, Coloma, California, USA\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Photo gallery of gold:\n\u003C\u002Fp>\nwww.mindat.org\u002Fgallery.php?min=1720",2080,1126,[],[273,274,275],"Colomit","Colomita","Colomite",[277,281,286,290,294,297,302,306,309,313,317],{"lang":278,"names":279},"ca",[280],"roscoelita",{"lang":282,"names":283},"de",[284,285],"Roscoelith","Vanadinglimmer",{"lang":287,"names":288},"eu",[289],"Roscoelita",{"lang":291,"names":292},"fr",[293],"roscoélite",{"lang":295,"names":296},"it",[7],{"lang":298,"names":299},"ja",[300,301],"ロスコーライト","ロスコー雲母",{"lang":303,"names":304},"nl",[305],"roscoeliet",{"lang":307,"names":308},"pt",[289],{"lang":310,"names":311},"ru",[312],"Роскоэлит",{"lang":314,"names":315},"sv",[316],"Roscoelit",{"lang":318,"names":319},"uk",[320],"Росколіт","Q2091836",{"history":11,"applications":11}]