Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
Category
Browse organic gemstone (not a rock or mineral in the traditional sense, but bio mineralized material) specimens identified by the Rock Identifier community.
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
Black Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Tiger's Eye
Pseudomorph of Crocidolite (SiO2 with iron oxides)
Pink Feldspar
Orthoclase Feldspar (KAlSi3O8)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Blue Kyanite
Kyanite (Al2SiO5)
Ironstone with Pyrite
Ferruginous Sandstone (Fe2O3) with minor Sulfide minerals (FeS2)
Kimberlite
Kimberlite
Black Opal
Hydrated Silica (SiO2·nH2O)
Rough Quartz (with potential Host Rock)
Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Almandine Garnet
Almandine (Fe3Al2Si3O12)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Mica Schist
Mica Schist (Complex Silicate Rock)
Quartz (Milky or Clear Quartz fragment)
Silicon Dioxide (SiO2)
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Granite
Granite (felsic intrusive igneous rock)
Prehnite on Basalt
Prehnite - Ca2Al(AlSi3O10)(OH)2
Quartz (Milky and Bull Quartz)
Silicon Dioxide (SiO2)
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
Diorite
Diorite (Intermediate intrusive igneous rock)
Diamond
Diamond (Carbon, C)
Chert (Flint variety)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Carnelian Agate
Carnelian (SiO2 with iron oxide impurities)
Rough Diamond
Diamond (Native Carbon), C
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Montana Moss Agate
Chalcedony (Silicon Dioxide, SiO2)
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Quartz Geode (Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Sugilite
KNa2(Fe,Mn,Al)2Li3Si12O30 (Potassium Sodium Lithium Iron Manganese Aluminum Silicate)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminium phosphate)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Diamond
Carbon (C)
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (high silica volcanic rock)