Amethyst
Amethyst (SiO2 with Iron impurities)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (SiO2 with Iron impurities)
Crushed Limestone
Calcite-rich Sedimentary Rock (CaCO3)
Turquoise
Hydrated phosphate of copper and aluminium: CuAl6(PO4)4(OH)8·4H2O
Petrified Wood
Silicified wood (primarily Silicon Dioxide - SiO2)
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2 - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Bauxite Ore
Hydrated aluminum oxides (e.g., Gibbsite Al(OH)3, Boehmite ̲̲̲̲AlOOH, Diaspore ̲̲̲̲AlOOH)
Chert Pebble (Jasper variety)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2)
Moss Agate
Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide
Pumice
Pumice (volcanic rock)
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Hypersthene
Hypersthene (formula: (Mg,Fe)SiO3)
Red Jasper (Heliotrope family variant)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert / Quartz Pebble
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amber
Succinite (fossilized resin)
Labradorite (Feldspar)
Labradorite, (Ca,Na)(Al,Si)4O8
Peridot in Basalt
Olivine ((Mg, Fe)2SiO4) in Basalt
Amethyst Geode
Silicon Dioxide with impurities (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Turquoise
Turquoise (Hydrated phosphate of copper and aluminium) CuAl6(PO4)4(OH)8·4H2O
Milky Quartz
Silicon Dioxide (SiO2)
Banded Chert (or Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO₂)
Granite
Granite (a felsic intrusive igneous rock)
Carnelian and White Quartz Bracelet
Silicon Dioxide (SiO2) - specifically Carnelian (Chalcedony) and Rock Crystal/Snow Quartz
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Carnelian
Carnelian (subset of Chalcedony); SiO2 with Iron Oxide impurities
Unakite
Unakite (Metasomatized Granodiorite)
Anthropogenic Heat Source (Electronic/Industrial Interface)
Thermal IR emission (Electronic infrastructure)
Unakite
Epidotized Granite
Serpentine
Serpentinite (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Quartz (Milky/Granular)
Silicon Dioxide (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2)