Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide)
Category
Browse organic gemstone (fossilized resin) specimens identified by the Rock Identifier community.
Amethyst (variety of Quartz)
SiO2 (Silicon Dioxide)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Limonite (Iron Ore)
Limonite (Hydrated iron oxide - FeO(OH)·nH2O)
Turquoise (possible Dyed Howlite or Magnesite imitation)
CuAl6(PO4)4(OH)8·4H2O (Turquoise)
Turquoise (Tumbled/Polished)
Hydrated phosphate of copper and aluminium, CuAl6(PO4)4(OH)8·4H2O
Yellow Jasper
Jasper (Silicon Dioxide, SiO2 plus various mineral impurities)
Garnet (Almandine/Pyrope series)
Silicate mineral (Almandine: Fe3Al2Si3O12; Pyrope: Mg3Al2Si3O12)
Red Cubic Zirconia (Simulated Garnet)
Zirconium Dioxide (ZrO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Sodalite
Sodalite Na8(Al6Si6O24)Cl2
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Yellow Quartz Pebble (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Unakite
Epidotized Granite
Quartz (Smoky/Grey variety)
Silicon Dioxide (SiO2)
Epidote
Epidote (Ca2(Al2,Fe3+)AlSi3O12(OH))
Tiger's Eye
Pseudomorph of Chalcedony (SiO2) after Crocidolite
Pyrite
Iron Sulfide (FeS2)
Black Obsidian
Obsidian (Amorphous volcanic glass, SiO2)
Obsidian
Obsidian (volcanic glass), primarily SiO2 (silicon dioxide)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Lapis Lazuli
Lapis Lazuli (Complex aggregate of Lazurite, Calcite, and Pyrite)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Milky Quartz
Silicon Dioxide (SiO2)
Epidote in Basalt
Epidotized Basalt (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH) in Mafic Igneous Host)
Amethyst (as seen in jewelry)
Amethyst (Silicon Dioxide SiO2 + Fe4+)
Tiger's Eye
SiO2 (Silicon Dioxide with iron inclusions)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Jasper
Silicon dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Emerald in Matrix
Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Labradorite
Labradorite (Plagioclase Feldspar series; (Ca,Na)(Al,Si)4O8)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities and irradiation)
Clear Quartz
Crystalline Silicon Dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron oxide inclusions)
Unakite
Unakite (Epidotized Granite)
Sunstone with Moonstone (Peach Moonstone)
Orthoclase Feldspar (KAlSi3O8)
Almandine Garnet
Iron aluminum silicate (Fe3Al2(SiO4)3)
Rough Star Sapphire (Corundum)
Al2O3 (Aluminum Oxide)