[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"minerals:one:9410":3},{"id":4,"longid":5,"guid":6,"name":7,"shortcode_ima":8,"entrytype":9,"entrytype_text":10,"varietyof":8,"synid":8,"polytypeof":8,"groupid":8,"weighting":11,"nolocadd":12,"blacklisted":13,"mindat_formula":8,"mindat_formula_note":8,"ima_formula":8,"elements":8,"sigelements":8,"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":14,"strunz10ed2":14,"strunz10ed3":14,"strunz10ed4":8,"dana8ed1":14,"dana8ed2":14,"dana8ed3":14,"dana8ed4":14,"csystem":8,"cclass":8,"spacegroup":8,"spacegroupset":14,"a":14,"b":14,"c":14,"alpha":14,"beta":14,"gamma":14,"aerror":8,"berror":8,"cerror":8,"alphaerror":8,"betaerror":8,"gammaerror":8,"va3":8,"z":8,"csmetamict":12,"commentcrystal":8,"twinning":8,"tranglide":8,"parting":8,"epitaxidescription":8,"morphology":8,"tlform":8,"hmin":8,"hmax":8,"hardtype":8,"vhnmin":14,"vhnmax":14,"vhnerror":8,"vhng":8,"vhns":8,"commenthard":8,"dmeas":14,"dmeas2":14,"dcalc":14,"dmeaserror":8,"dcalcerror":8,"commentdense":8,"lustre":8,"lustretype":8,"commentluster":8,"diapheny":8,"streak":8,"colour":8,"commentcolor":8,"colors":8,"streak_colors":8,"luminescence":8,"uv":8,"cleavage":8,"cleavagetype":8,"fracturetype":8,"tenacity":8,"commentbreak":8,"opticaltype":8,"opticalsign":8,"opticalalpha":14,"opticalalpha2":14,"opticalalphaerror":8,"opticalbeta":14,"opticalbeta2":14,"opticalbetaerror":8,"opticalgamma":14,"opticalgamma2":14,"opticalgammaerror":8,"opticalomega":14,"opticalomega2":14,"opticalomegaerror":8,"opticalepsilon":14,"opticalepsilon2":14,"opticalepsilonerror":8,"opticaln":14,"opticaln2":14,"opticalnerror":8,"optical2vcalc":14,"optical2vcalc2":14,"optical2vcalcerror":8,"optical2vmeasured":14,"optical2vmeasured2":14,"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":8,"type_specimen_store":8,"description_short":8,"aboutname":8,"rock_parent":8,"rock_parent2":8,"rock_root":9,"rock_bgs_code":8,"meteoritical_code":8,"updttime":15,"reviewed_at":8,"variety_of":8,"varieties":16,"group_members":24,"associates":25,"confused_with":26,"type_localities":27,"occurrence_total":28,"citations":29,"images":30,"structures":122,"synonyms":123,"language_names":137,"wikidata_qid":8,"texts":138},9410,"1:1:9410:4","acd1548e-cf14-4410-bebc-4f164d24a066","Pinite",null,0,"mineral",535,false,true,"0","2025-08-11 12:14:30",[17,21],{"id":18,"name":19,"entrytype":20,"csystem":8,"ima_formula":8,"mindat_formula":8,"hmin":8,"hmax":8,"dmeas":14,"dcalc":8,"primary_image_id":8},9411,"Cordierite-pinite",2,{"id":22,"name":23,"entrytype":20,"csystem":8,"ima_formula":8,"mindat_formula":8,"hmin":8,"hmax":8,"dmeas":14,"dcalc":14,"primary_image_id":8},9413,"Polychroilite",[],[],[],[],97,[],[31,38,47,57,67,75,84,91,98,106,114],{"id":32,"source_url":33,"license_code":34,"credit_html":35,"title":7,"description":8,"author":8,"original_width":36,"original_height":37},30468,"https:\u002F\u002Fgeocollections.info\u002Ffile\u002F130780","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\u002F130780\" rel=\"noopener\">University of Tartu, Natural History Museum\u003C\u002Fa> via Europeana",1000,645,{"id":39,"source_url":40,"license_code":34,"credit_html":41,"title":42,"description":43,"author":44,"original_width":45,"original_height":46},74281,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=83084283","Mai Seppel, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=83084283\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Estonian Museum of Natural History Specimen No 202385 photo (g27 g27-748 1 jpg).jpg","\"mineraalid\", \"piniit\". More info \u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fgeocollections.info\u002Ffile\u002F65374\">about this file\u003C\u002Fa> and \u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fgeocollections.info\u002Fspecimen\u002F202385\">about this specimen\u003C\u002Fa> at \u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fgeocollections.info\u002F\">geocollections.info\u003C\u002Fa>","Mai Seppel",2894,2618,{"id":48,"source_url":49,"license_code":50,"credit_html":51,"title":52,"description":53,"author":54,"original_width":55,"original_height":56},19483,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10175071","CC BY-SA 3.0","Robert M. Lavinsky, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=10175071\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Pinite-33956.jpg","\u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FPinite\" class=\"extiw\" title=\"en:Pinite\">Pinite\u003C\u002Fa>\n\u003Cdl>\u003Cdd>\u003Cdl>\u003Cdd>Locality: \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FV%C3%A4sterby\" class=\"extiw\" title=\"en:Västerby\">Västerby\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FAskersund\" class=\"extiw\" title=\"en:Askersund\">Askersund\u003C\u002Fa>, \u003Ca href=\"https:\u002F\u002Fen.wikipedia.org\u002Fwiki\u002FN%C3%A4rke\" class=\"extiw\" title=\"en:Närke\">Närke\u003C\u002Fa>, Sweden (\u003Ca rel=\"nofollow\" class=\"external text\" href=\"http:\u002F\u002Fwww.mindat.org\u002Floc-12006.html\">Locality at mindat.org\u003C\u002Fa>)\u003C\u002Fdd>\n\u003Cdd>Pinite is not a valid species but is rather a mixture of other rockforming species that replace certain silicate minerals, such as cordierite in particular. This is, I am told, a really really good and not-as-ugly-as-usual specimen of incredibly large cordierite crystals replaced by this mix of mica and other minerals, Neat old label, too! 15 x 10.6 x 9.3 cm\u003C\u002Fdd>\u003C\u002Fdl>\u003C\u002Fdd>\u003C\u002Fdl>","Robert M. Lavinsky",600,518,{"id":58,"source_url":59,"license_code":60,"credit_html":61,"title":62,"description":63,"author":64,"original_width":65,"original_height":66},19484,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560060","CC BY 2.0","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560060\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) (muscovite mica replacing intergrown cordierite-indialite) (mid-Cretaceous, 98 Ma; Kameoka, Honshu Island, Japan) 2.jpg","“Cherry blossom stones” - pinite (= muscovite mica replacing intergrown cordierite-indialite) from Kameoka, west of Kyoto, Kyoto Prefecture, southwestern Honshu Island, southern Japan.  (Limper Geology Museum specimens, Miami University, Oxford, Ohio, USA)\n\u003Chr>\n\u003Cp>One of the most famous & visually intriguing geologic materials collected in Japan is the cherry blossom stone.  These interesting structures have a complex geologic history.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What are they now?\nCherry blossom stones are relatively small, subhexagonal-shaped masses of fine-grained muscovite mica that show a flower-like pattern in transverse cross-section.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What did they used to be?\nThe muscovite mica is not the original material making up these structures.  Before the growth of muscovite mica, these were complex intergrowths of six cordierite crystals and one indialite crystal.  So, cherry blossom stones represent muscovite mica replacing cordierite-indialite (muscovite pseudomorphs after cordierite-indialite).  Such complex pseudomorphs have been referred to as pinite.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What is the host rock?\nCherry blossom stones are hosted in a matrix of hornfels, a fine-grained, contact metamorphic rock.  Hornfels form by intense alteration (heating & chemical alteration) of shales by nearby lava or magma.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>How did they form?\nThe hornfels host rocks were originally fine-grained siliciclastic sedimentary rocks (shales) of the Tamba Group (Triassic-Jurassic-lowermost Cretaceous).  In the mid-Cretaceous (early Cenomanian Stage, ~98 m.y.), underground igneous activity resulted in granites and granodiorite intrusions altering the shales into hornfels by contact metamorphism.  These hornfels had decent-sized masses of intergrown cordierite-indialite.\n\u003C\u002Fp>\u003Cp>Indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18).  Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).  The subhexagonal-shaped masses of cordierite-indialite in the hornfels consist of seven individual crystals.  At the center of each mass is a dumbbell-shaped indialite crystal - very narrow at the center, and relatively wide at the ends (look at the varying sizes of the center hexagon in the cherry blossom stones shown above).  Surrounding the indialite crystal are six prism-shaped cordierite crystals.  They are widest at the center of each cherry blossom stone and narrowest at the ends.\n\u003C\u002Fp>\u003Cp>A second metamorphic event altered the cordierite-indialite masses.  Hydrothermal metamorphism resulted in fine-grained muscovite mica replacing the original minerals.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Much info. from:\n\u003C\u002Fp>\nRakovan et al. (2006) - Sakura Ishi (cherry blossom stones): mica pseudomorphs of complex cordierite-indialite intergrowths from Kameoka, Kyoto Prefecture, Japan.  in  Minerals from Japan.  Rocks & Minerals Reprint 2006: 31-39.","James St. John",1330,1216,{"id":68,"source_url":69,"license_code":60,"credit_html":70,"title":71,"description":72,"author":64,"original_width":73,"original_height":74},19485,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560061","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560061\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stone (pinite) (muscovite mica replacing intergrown cordierite-indialite) (mid-Cretaceous, 98 Ma; Kameoka, Honshu Island, Japan) 1.jpg","“Cherry blossom stone” (9 mm across) - pinite (= muscovite mica replacing intergrown cordierite-indialite) from Kameoka, west of Kyoto, Kyoto Prefecture, southwestern Honshu Island, southern Japan.  The small, central, hexagonal structure represents where indialite used to be.  The “petals” of the cherry blossom flower (= the 6 wedge-shaped masses surrounding the center hexagon) represent where cordierite used to be.\n\u003Chr>\n\u003Cp>One of the most famous & visually intriguing geologic materials collected in Japan is the cherry blossom stone.  These interesting structures have a complex geologic history.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What are they now?\nCherry blossom stones are relatively small, subhexagonal-shaped masses of fine-grained muscovite mica that show a flower-like pattern in transverse cross-section.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What did they used to be?\nThe muscovite mica is not the original material making up these structures.  Before the growth of muscovite mica, these were complex intergrowths of six cordierite crystals and one indialite crystal.  So, cherry blossom stones represent muscovite mica replacing cordierite-indialite (muscovite pseudomorphs after cordierite-indialite).  Such complex pseudomorphs have been referred to as pinite.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What is the host rock?\nCherry blossom stones are hosted in a matrix of hornfels, a fine-grained, contact metamorphic rock.  Hornfels form by intense alteration (heating & chemical alteration) of shales by nearby lava or magma.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>How did they form?\nThe hornfels host rocks were originally fine-grained siliciclastic sedimentary rocks (shales) of the Tamba Group (Triassic-Jurassic-lowermost Cretaceous).  In the mid-Cretaceous (early Cenomanian Stage, ~98 m.y.), underground igneous activity resulted in granites and granodiorite intrusions altering the shales into hornfels by contact metamorphism.  These hornfels had decent-sized masses of intergrown cordierite-indialite.\n\u003C\u002Fp>\u003Cp>Indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18).  Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).  The subhexagonal-shaped masses of cordierite-indialite in the hornfels consist of seven individual crystals.  At the center of each mass is a dumbbell-shaped indialite crystal - very narrow at the center, and relatively wide at the ends (look at the varying sizes of the center hexagon in the cherry blossom stones in this photo album).  Surrounding the indialite crystal are six prism-shaped cordierite crystals.  They are widest at the center of each cherry blossom stone and narrowest at the ends.\n\u003C\u002Fp>\u003Cp>A second metamorphic event altered the cordierite-indialite masses.  Hydrothermal metamorphism resulted in fine-grained muscovite mica replacing the original minerals.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Much info. from:\n\u003C\u002Fp>\nRakovan et al. (2006) - Sakura Ishi (cherry blossom stones): mica pseudomorphs of complex cordierite-indialite intergrowths from Kameoka, Kyoto Prefecture, Japan.  in  Minerals from Japan.  Rocks & Minerals Reprint 2006: 31-39.",666,642,{"id":76,"source_url":77,"license_code":60,"credit_html":78,"title":79,"description":80,"author":81,"original_width":82,"original_height":83},60721,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=74327920","James St. John (jsj1771) (https:\u002F\u002Fwww.flickr.com\u002Fpeople\u002Fjsjgeology\u002F), via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=74327920\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Hornfels from Mikata on Honshu in Japan.jpg","Hornfels with pinite (= muscovite mica replacing intergrown cordierite-indialite; “cherry blossom stones”), Tamba Group, Mesozoic (Triassic to lowermost Cretaceous), ~98 m.y. contact metamorphic date. \n\u003Cp>Locality: at or near Mikata, Mikata District, Fukui Prefecture, Honshu Island, southern Japan. \n\u003C\u002Fp>\n(Limper Geology Museum specimen, Miami University, Oxford, Ohio, USA)","James St. John (jsj1771) (https:\u002F\u002Fwww.flickr.com\u002Fpeople\u002Fjsjgeology\u002F)",2908,1723,{"id":85,"source_url":86,"license_code":60,"credit_html":87,"title":88,"description":63,"author":64,"original_width":89,"original_height":90},19486,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560064","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560064\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) (muscovite mica replacing intergrown cordierite-indialite) (mid-Cretaceous, 98 Ma; Kameoka, Honshu Island, Japan) 4.jpg",1132,1237,{"id":92,"source_url":93,"license_code":60,"credit_html":94,"title":95,"description":63,"author":64,"original_width":96,"original_height":97},19487,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560065","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560065\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) (muscovite mica replacing intergrown cordierite-indialite) (mid-Cretaceous, 98 Ma; Kameoka, Honshu Island, Japan) 3.jpg",1060,1048,{"id":99,"source_url":100,"license_code":60,"credit_html":101,"title":102,"description":103,"author":64,"original_width":104,"original_height":105},19488,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560067","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560067\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) in hornfels (mid-Cretaceous, 98 Ma; Mikata, Honshu Island, Japan) 2.jpg","Hornfels with pinite (= muscovite mica replacing intergrown cordierite-indialite; “cherry blossom stones”), Tamba Group, Mesozoic (Triassic to lowermost Cretaceous), ~98 m.y. contact metamorphic date.\n\u003Cp>Locality: at or near Ashio, Tochigi Prefecture, Honshu Island, central Japan\n\u003C\u002Fp>\u003Cp>(Limper Geology Museum specimen, Miami University, Oxford, Ohio, USA)\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>One of the most famous & visually intriguing geologic materials collected in Japan is the cherry blossom stone.  These interesting structures have a complex geologic history.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What are they now?\nCherry blossom stones are relatively small, subhexagonal-shaped masses of fine-grained muscovite mica that show a flower-like pattern in transverse cross-section.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What did they used to be?\nThe muscovite mica is not the original material making up these structures.  Before the growth of muscovite mica, these were complex intergrowths of six cordierite crystals and one indialite crystal.  So, cherry blossom stones represent muscovite mica replacing cordierite-indialite (muscovite pseudomorphs after cordierite-indialite).  Such complex pseudomorphs have been referred to as pinite.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What is the host rock?\nCherry blossom stones are hosted in a matrix of hornfels, a fine-grained, contact metamorphic rock.  Hornfels form by intense alteration (heating & chemical alteration) of shales by nearby lava or magma.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>How did they form?\nThe hornfels host rocks were originally fine-grained siliciclastic sedimentary rocks (shales) of the Tamba Group (Triassic-Jurassic-lowermost Cretaceous).  In the mid-Cretaceous (early Cenomanian Stage, ~98 m.y.), underground igneous activity resulted in granites and granodiorite intrusions altering the shales into hornfels by contact metamorphism.  These hornfels had decent-sized masses of intergrown cordierite-indialite.\n\u003C\u002Fp>\u003Cp>Indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18).  Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).  The subhexagonal-shaped masses of cordierite-indialite in the hornfels consist of seven individual crystals.  At the center of each mass is a dumbbell-shaped indialite crystal - very narrow at the center, and relatively wide at the ends (look at the varying sizes of the center hexagon in the cherry blossom stones in this photo album).  Surrounding the indialite crystal are six prism-shaped cordierite crystals.  They are widest at the center of each cherry blossom stone and narrowest at the ends.\n\u003C\u002Fp>\u003Cp>A second metamorphic event altered the cordierite-indialite masses.  Hydrothermal metamorphism resulted in fine-grained muscovite mica replacing the original minerals.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Much info. from:\n\u003C\u002Fp>\nRakovan et al. (2006) - Sakura Ishi (cherry blossom stones): mica pseudomorphs of complex cordierite-indialite intergrowths from Kameoka, Kyoto Prefecture, Japan.  in  Minerals from Japan.  Rocks & Minerals Reprint 2006: 31-39.",1886,959,{"id":107,"source_url":108,"license_code":60,"credit_html":109,"title":110,"description":111,"author":64,"original_width":112,"original_height":113},19489,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560068","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560068\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) in hornfels (mid-Cretaceous, 98 Ma; Mikata, Honshu Island, Japan) 3.jpg","Hornfels with pinite (= muscovite mica replacing intergrown cordierite-indialite; “cherry blossom stones”), Tamba Group, Mesozoic (Triassic to lowermost Cretaceous), ~98 m.y. contact metamorphic date.  (Limper Geology Museum specimen, Miami University, Oxford, Ohio, USA)\n\u003Chr>\n\u003Cp>One of the most famous & visually intriguing geologic materials collected in Japan is the cherry blossom stone.  These interesting structures have a complex geologic history.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What are they now?\nCherry blossom stones are relatively small, subhexagonal-shaped masses of fine-grained muscovite mica that show a flower-like pattern in transverse cross-section.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What did they used to be?\nThe muscovite mica is not the original material making up these structures.  Before the growth of muscovite mica, these were complex intergrowths of six cordierite crystals and one indialite crystal.  So, cherry blossom stones represent muscovite mica replacing cordierite-indialite (muscovite pseudomorphs after cordierite-indialite).  Such complex pseudomorphs have been referred to as pinite.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What is the host rock?\nCherry blossom stones are hosted in a matrix of hornfels, a fine-grained, contact metamorphic rock.  Hornfels form by intense alteration (heating & chemical alteration) of shales by nearby lava or magma.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>How did they form?\nThe hornfels host rocks were originally fine-grained siliciclastic sedimentary rocks (shales) of the Tamba Group (Triassic-Jurassic-lowermost Cretaceous).  In the mid-Cretaceous (early Cenomanian Stage, ~98 m.y.), underground igneous activity resulted in granites and granodiorite intrusions altering the shales into hornfels by contact metamorphism.  These hornfels had decent-sized masses of intergrown cordierite-indialite.\n\u003C\u002Fp>\u003Cp>Indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18).  Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).  The subhexagonal-shaped masses of cordierite-indialite in the hornfels consist of seven individual crystals.  At the center of each mass is a dumbbell-shaped indialite crystal - very narrow at the center, and relatively wide at the ends (look at the varying sizes of the center hexagon in the cherry blossom stones in this photo album).  Surrounding the indialite crystal are six prism-shaped cordierite crystals.  They are widest at the center of each cherry blossom stone and narrowest at the ends.\n\u003C\u002Fp>\u003Cp>A second metamorphic event altered the cordierite-indialite masses.  Hydrothermal metamorphism resulted in fine-grained muscovite mica replacing the original minerals.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Much info. from:\n\u003C\u002Fp>\nRakovan et al. (2006) - Sakura Ishi (cherry blossom stones): mica pseudomorphs of complex cordierite-indialite intergrowths from Kameoka, Kyoto Prefecture, Japan.  in  Minerals from Japan.  Rocks & Minerals Reprint 2006: 31-39.",1513,1108,{"id":115,"source_url":116,"license_code":60,"credit_html":117,"title":118,"description":119,"author":64,"original_width":120,"original_height":121},19490,"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560080","James St. John, via \u003Ca href=\"https:\u002F\u002Fcommons.wikimedia.org\u002F?curid=97560080\" rel=\"noopener\">Wikimedia Commons\u003C\u002Fa>","Cherry blossom stones (pinite) in hornfels (mid-Cretaceous, 98 Ma; Mikata, Honshu Island, Japan) 4.jpg","Pinite in weathered hornfels from the Cretaceous of Japan. (~2.55 centimeters across at its widest)\n\u003Cp>One of the most famous & visually intriguing geologic materials collected in Japan is the cherry blossom stone.  These interesting structures have a complex geologic history.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What are they now?\nCherry blossom stones are relatively small, subhexagonal-shaped masses of fine-grained muscovite mica that show a flower-like pattern in transverse cross-section.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What did they used to be?\nThe muscovite mica is not the original material making up these structures.  Before the growth of muscovite mica, these were complex intergrowths of six cordierite crystals and one indialite crystal.  So, cherry blossom stones represent muscovite mica replacing cordierite-indialite (muscovite pseudomorphs after cordierite-indialite).  Such complex pseudomorphs have been referred to as pinite.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>What is the host rock?\nCherry blossom stones are hosted in a matrix of hornfels, a fine-grained, contact metamorphic rock.  Hornfels form by intense alteration (heating & chemical alteration) of shales by nearby lava or magma.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>How did they form?\nThe hornfels host rocks were originally fine-grained siliciclastic sedimentary rocks (shales) of the Tamba Group (Triassic-Jurassic-lowermost Cretaceous).  During the mid-Cretaceous (early Cenomanian Stage, ~98 million years ago), underground igneous activity resulted in granites and granodiorite intrusions altering the shales into hornfels by contact metamorphism.  These hornfels had decent-sized masses of intergrown cordierite-indialite.\n\u003C\u002Fp>\u003Cp>Indialite is a magnesium aluminosilicate mineral (Mg2Al4Si5O18).  Cordierite is an iron magnesium aluminosilicate mineral ((Fe,Mg)2Al4Si5O18).  The subhexagonal-shaped masses of cordierite-indialite in the hornfels consist of seven individual crystals.  At the center of each mass is a dumbbell-shaped indialite crystal - very narrow at the center, and relatively wide at the ends (see the varying sizes of the center hexagon in other cherry blossom stones elsewhere in this photo album).  Surrounding the indialite crystal are six prism-shaped cordierite crystals.  They are widest at the center of each cherry blossom stone and narrowest at the ends.\n\u003C\u002Fp>\u003Cp>A second metamorphic event altered the cordierite-indialite masses.  Hydrothermal metamorphism resulted in fine-grained muscovite mica replacing the original minerals.\n\u003C\u002Fp>\u003Cp>Stratigraphy: Tamba Group, Mesozoic (Triassic to lowermost Cretaceous), ~98 Ma contact metamorphic date\n\u003C\u002Fp>\u003Cp>Locality: at or near Mikata, Mikata District, Fukui Prefecture, Honshu Island, southern Japan.\n\u003C\u002Fp>\n\u003Chr>\n\u003Cp>Much info. from:\n\u003C\u002Fp>\nRakovan et al. (2006) - Sakura Ishi (cherry blossom stones): mica pseudomorphs of complex cordierite-indialite intergrowths from Kameoka, Kyoto Prefecture, Japan.  in  Minerals from Japan.  Rocks & Minerals Reprint 2006: 31-39.",1699,1444,[],[124,125,126,127,128,129,130,131,132,133,134,135,136],"Cataspilit","Cataspilita","Cataspilite","Peploit","Peplolit","Peplolita","Peplolite","Pinit","Pinita","Pinnit","Pinnita","Pinnite","Speckstein (of Hoffmann)",[],{"history":8,"applications":8}]