Llanite (original) (raw)
Llanite is a porphyritic rhyolite with distinctive phenocrysts of blue quartz (a rare quartz color) and perthitic feldspar (light grayish-orangish). The brown, fine-grained groundmass consists of very small quartz, feldspar, and biotite mica crystals. Llanite comes from a hypabyssal porphyritic rhyolite dike that intrudes Precambrian metamorphics in the Llano Uplift of central Texas. Published radiometric dating on this llanite indicates that it's 1.106 billion years old (late Mesoproterozoic). It is named after Llano County, Texas, the only place where it is found. Modal mineralogy of llanite:
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| dbo:abstract | Llanite is a porphyritic rhyolite with distinctive phenocrysts of blue quartz (a rare quartz color) and perthitic feldspar (light grayish-orangish). The brown, fine-grained groundmass consists of very small quartz, feldspar, and biotite mica crystals. Llanite comes from a hypabyssal porphyritic rhyolite dike that intrudes Precambrian metamorphics in the Llano Uplift of central Texas. Published radiometric dating on this llanite indicates that it's 1.106 billion years old (late Mesoproterozoic). The quartz crystals found in llanite are blue hexagonal bipyramids. The unusual blue coloration of the quartz is thought to be due to ilmenite inclusions. It is named after Llano County, Texas, the only place where it is found. However, the geology of North-East Africa is very similar to that of Texas. Many of the minerals and fossils found are only found in these two locations on the whole planet.(geologists have identified other locations where similar types of rock may be found). A dike of llanite crops out on Texas State Highway 16 approximately nine miles north of the town of Llano. Llanite, which is similar to granite, is very strong, with a crushing strength of 37,800 lb/in2 or 26,577,180 kg/m2. Llanite is also very similar in appearance to pietersite. Modal mineralogy of llanite: * quartz - 34.6% * microcline - 27.8% * plagioclase - 27.9% * biotite - 8.6% * fluorite - 1.1% * apatite - 0.14% * magnetite - trace * ilmenite - trace * zircon - trace (en) |
| dbo:thumbnail | wiki-commons:Special:FilePath/Llanite.jpg?width=300 |
| dbo:wikiPageExternalLink | https://hgms.org/BBG_Archives/2014/HGMS-BBG-May2014.pdf http://www.hgms.org/ |
| dbo:wikiPageID | 3027819 (xsd:integer) |
| dbo:wikiPageLength | 3360 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 1095114986 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Bipyramid dbr:Llano_Uplift dbc:Igneous_rocks dbr:Llano_County,_Texas dbr:Dike_(geology) dbr:File:Llanite.jpg dbr:Texas_State_Highway_16 dbr:Porphyry_(geology) dbr:Ilmenite dbr:Pietersite dbr:File:Llanite2.jpg dbr:File:Map_of_Texas_highlighting_Llano_County.svg |
| dbp:wikiPageUsesTemplate | dbt:Reflist dbt:Petrology-stub |
| dcterms:subject | dbc:Igneous_rocks |
| rdf:type | yago:Abstraction100002137 yago:IgneousRock114931879 yago:Material114580897 yago:Matter100020827 yago:Part113809207 yago:PhysicalEntity100001930 yago:Relation100031921 yago:WikicatIgneousRocks yago:Rock114696793 yago:Substance100019613 |
| rdfs:comment | Llanite is a porphyritic rhyolite with distinctive phenocrysts of blue quartz (a rare quartz color) and perthitic feldspar (light grayish-orangish). The brown, fine-grained groundmass consists of very small quartz, feldspar, and biotite mica crystals. Llanite comes from a hypabyssal porphyritic rhyolite dike that intrudes Precambrian metamorphics in the Llano Uplift of central Texas. Published radiometric dating on this llanite indicates that it's 1.106 billion years old (late Mesoproterozoic). It is named after Llano County, Texas, the only place where it is found. Modal mineralogy of llanite: (en) |
| rdfs:label | Llanite (en) |
| owl:sameAs | freebase:Llanite yago-res:Llanite wikidata:Llanite https://global.dbpedia.org/id/fDxy |
| prov:wasDerivedFrom | wikipedia-en:Llanite?oldid=1095114986&ns=0 |
| foaf:depiction | wiki-commons:Special:FilePath/Llanite2.jpg wiki-commons:Special:FilePath/Map_of_Texas_highlighting_Llano_County.svg wiki-commons:Special:FilePath/Llanite.jpg |
| foaf:isPrimaryTopicOf | wikipedia-en:Llanite |
| is dbo:wikiPageWikiLink of | dbr:List_of_gemstones_by_species dbr:Llano,_Texas dbr:Llano_Uplift dbr:Que_sera dbr:Llano |
| is foaf:primaryTopic of | wikipedia-en:Llanite |
