Rock Identifier

Category

Mineral (Organic Gemstone)

Browse mineral (organic gemstone) specimens identified by the Rock Identifier community.

Moonstone (Potassium Aluminum Silicate (KAlSi3O8)) — mineral

Moonstone

Potassium Aluminum Silicate (KAlSi3O8)

Olivine (Peridot) (Magnesium Iron Silicate (Mg,Fe)2SiO4) — mineral

Olivine (Peridot)

Magnesium Iron Silicate (Mg,Fe)2SiO4

Chert (Jasper/Flint variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pearl (Aragonite (CaCO3) with Conchiolin) — mineral

Pearl

Aragonite (CaCO3) with Conchiolin

Dendritic Limestone (Calcite with Manganese Oxide (Manganese Dendrites)) — sedimentary

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Chert (often called Flint or Jasper if reddish) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper if reddish)

Microcrystalline Quartz (SiO2)

Sunstone (Oligoclase (Plagioclase Feldspar subclass), (Ca,Na)(Al,Si)4O8) — mineral

Sunstone

Oligoclase (Plagioclase Feldspar subclass), (Ca,Na)(Al,Si)4O8

Amethyst (Rough Crystal) (Silicon Dioxide (SiO2 with ferric iron impurities)) — mineral

Amethyst (Rough Crystal)

Silicon Dioxide (SiO2 with ferric iron impurities)

Chrysocolla on Matrix (Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O) — mineral

Chrysocolla on Matrix

Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4·nH2O

Amethyst (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Citrine Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Rough Tanzanite (Zoisite (Ca2Al3(SiO4)3(OH))) — mineral

Rough Tanzanite

Zoisite (Ca2Al3(SiO4)3(OH))

Chrysocolla (Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)) — mineral

Chrysocolla

Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)

Amazonite (Amazonite (KAlSi3O8)) — mineral

Amazonite

Amazonite (KAlSi3O8)

Citrine (Heat-treated or Natural Quartz) (Silicon Dioxide (SiO2)) — mineral

Citrine (Heat-treated or Natural Quartz)

Silicon Dioxide (SiO2)

Citrine (Quartz (Silicon Dioxide - SiO2)) — mineral

Citrine

Quartz (Silicon Dioxide - SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Amethyst (Amethyst (SiO2 with iron impurities)) — mineral

Amethyst

Amethyst (SiO2 with iron impurities)

Amazonite (K(AlSi3O8) - Microcline variant) — mineral

Amazonite

K(AlSi3O8) - Microcline variant

Moldavite (Moldavite (Siliceous vitreous substance)) — tektite (natural glass)

Moldavite

Moldavite (Siliceous vitreous substance)

tektite (natural glass)

Amethyst (Amethyst (Silicon Dioxide, SiO2)) — mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

Amazonite (Potassium aluminum silicate (Microcline); KAlSi3O8) — mineral

Amazonite

Potassium aluminum silicate (Microcline); KAlSi3O8

Amazonite (or Amazon Stone) (Potassium Feldspar (Microcline), K(AlSi3O8)) — mineral

Amazonite (or Amazon Stone)

Potassium Feldspar (Microcline), K(AlSi3O8)

Clear Quartz (SiO2 (Silicon Dioxide)) — mineral

Clear Quartz

SiO2 (Silicon Dioxide)

Prehnite (Prehnite - Ca2Al(AlSi3O10)(OH)2) — mineral

Prehnite

Prehnite - Ca2Al(AlSi3O10)(OH)2

Amazonite (Microcline (Amazonstone), K(AlSi3O8)) — mineral

Amazonite

Microcline (Amazonstone), K(AlSi3O8)

Sandstone Chert Concretion (Silica-cemented Concretion (primarily SiO2)) — sedimentary

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Chert Pebble (Jasper/Quartz variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble (Jasper/Quartz variety)

Microcrystalline Quartz (SiO2)

Mother of Pearl (Nacre) (Aragonite (layered with organic polymers), CaCO3) — mineral

Mother of Pearl (Nacre)

Aragonite (layered with organic polymers), CaCO3

Purple Agate (Dyed Chalcedony) (SiO2 (Silicon Dioxide) with organic dyes) — mineral

Purple Agate (Dyed Chalcedony)

SiO2 (Silicon Dioxide) with organic dyes

Blue Tiger's Eye (Crocidolite in Quartz (altered)) — Mineral

Blue Tiger's Eye

Crocidolite in Quartz (altered)

Epidote (Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))) — mineral

Epidote

Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))

Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)) — mineral

Epidote

{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)

Red Jasper (Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — sedimentary

Red Jasper

Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Yellow Sapphire or Citrine (Al2O3 (Corundum) or SiO2 (Quartz)) — mineral

Yellow Sapphire or Citrine

Al2O3 (Corundum) or SiO2 (Quartz)

Quartz Geode (Silicon Dioxide (SiO2) within a secondary sedimentary structure) — sedimentary

Quartz Geode

Silicon Dioxide (SiO2) within a secondary sedimentary structure

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Jasper/Flint variety) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Quartz Geode in Chert/Limestone Matrix (Silicon Dioxide (SiO2) within Sedimentary Host Rock) — sedimentary

Quartz Geode in Chert/Limestone Matrix

Silicon Dioxide (SiO2) within Sedimentary Host Rock

Chert (Flint variety) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)