Garnet Schist
Garnetiferous Micaceous Schist
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Garnet Schist
Garnetiferous Micaceous Schist
Diamond
Diamond (C)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Quartz / Quartzite
Silicon Dioxide (SiO2)
Mahogany Obsidian
Volcanic Glass (predominantly SiO2 with Fe2O3 inclusions)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Citrine (Iron-stained Quartz)
Silicon Dioxide (SiO2)
Fire Agate
Chalcedony (Silicon Dioxide, SiO2) with Limonite/Goethite
Blue Lace Agate (Tumbled)
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Amygdaloidal Basalt
Vesicular Basalt with secondary mineral infilling (commonly Zeolites, Calcite, or Quartz)
Amethyst (Quartz)
Amethyst (SiO2 with iron impurities)
Carnelian
Carnelian (Cryptocrystalline Quartz, SiO2)
Diamond
Diamond (Pure Carbon, C)
Sandstone
Arenite
Jasper
Jasper (Silicate - SiO2)
Orange Quartzite / Carnelian Agate
Silicon Dioxide (SiO2)
Mixed collection of Quartz varieties, Chalcedony, and metamorphic pebbles
Mixed gemstones (primarily Silicon Dioxide - SiO2)
Quartzite
Quartzite (Primary mineral: SiO2)
Quartz (specifically Citrine or Yellow Quartzite pebble)
Silicon Dioxide (SiO2)
Garnet
Almandine formula: Fe3Al2(SiO4)3
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (Amorphous Silica)
Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Unidentifiable Rock Fragment
Turquoise
CuAl6(PO4)4(OH)8·4H2O
Kyanite (Blue Kyanite)
Kyanite (Al2SiO5)
Carnelian (Orange Agate)
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky Variety)
Silicon Dioxide (SiO2)
Diorite
Diorite (Intermediate intrusive igneous rock)
Epidote with Quartz/Feldspar
Epidote (Ca2(Al, Fe)3(SiO4)3(OH)) with associated minerals in a host rock
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Yellow Quartz (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Prehnite
Ca2Al(AlSi3O10)(OH)2 (Calcium Aluminum Silicate hydroxide)
Muscovite Mica
Muscovite (Potassium Mica) KAl2(AlSi3O10)(OH)2
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)