Rock Identifier

Category

Organic Gemstone (Not A Mineral)

Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.

Learn about Organic Gemstone (Not A Mineral) in the encyclopedia

Black Shale

Black Shale

Jet

Jet

Malachite

Malachite

Sapropel

Sapropel

Bituminous Shale

Bituminous Shale

Red Garnet

Red Garnet

Shungite

Shungite

Anatase

Anatase

Sperrylite

Sperrylite

Amber

Amber

Hutcheonite

Hutcheonite

Coal

Coal

Limestone with Chert or Siltstone bands (Sedimentary carbonate rock (CaCO3) often with siliceous impurities) — sedimentary

Limestone with Chert or Siltstone bands

Sedimentary carbonate rock (CaCO3) often with siliceous impurities

Shale (or Mudstone) (Siltstone/Argillite (composed mainly of clay and silt-sized particles)) — sedimentary

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

Smoky Quartz (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Precious Opal (Hydrated amorphous silica (SiO2·nH2O)) — mineral

Precious Opal

Hydrated amorphous silica (SiO2·nH2O)

Sunstone (Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)) — mineral

Sunstone

Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)

Chert (River Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline silica (SiO2)

Turquoise (CuAl6(PO4)4(OH)8·4H2O) — mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O

Chert (Red Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Red Jasper variant)

Microcrystalline Quartz (SiO2)

Chert (White Chert / Flint) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Green Aventurine (Silicon dioxide with Fuscite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)) — mineral

Green Aventurine

Silicon dioxide with Fuscite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

Ruby (Raw Corundum) (Corundum (Al2O3) with Chromium traces) — mineral

Ruby (Raw Corundum)

Corundum (Al2O3) with Chromium traces

Ferruginous Sandstone Concretion (Ironstone Phosphorite) (Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)) — sedimentary

Ferruginous Sandstone Concretion (Ironstone Phosphorite)

Ferruginous Sandstone (variable Fe-oxide/hydroxide composition)

Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

Fossilized Rugose Coral (Horn Coral) (Order Rugosa) — sedimentary

Fossilized Rugose Coral (Horn Coral)

Order Rugosa

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

Amazonite

Microcline (K(AlSi3O8))

Carnelian Agate (Silicon Dioxide (SiO2) with iron oxide impurities) — Mineral

Carnelian Agate

Silicon Dioxide (SiO2) with iron oxide impurities

Schorl (Black Tourmaline) (NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)) — mineral

Schorl (Black Tourmaline)

NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH)

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chrysocolla

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

Turquoise (CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)) — mineral

Turquoise

CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminum)

Picture Jasper (Silicon Dioxide (SiO2) with iron oxide and organic impurities) — sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and organic impurities

Chert with Quartz Druzy (Microcrystalline Quartz (SiO2) with Drusy Quartz Coating) — sedimentary

Chert with Quartz Druzy

Microcrystalline Quartz (SiO2) with Drusy Quartz Coating

Banded Chert (Cryptocrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Cryptocrystalline Quartz (SiO2)

Jasper (Silicon Dioxide (SiO2)) — sedimentary

Jasper

Silicon Dioxide (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Tufa (Calcareous Tufa) (Calcareous Tufa (Precipitated CaCO3)) — sedimentary

Tufa (Calcareous Tufa)

Calcareous Tufa (Precipitated CaCO3)

Variscite in Matrix (Variscite (AlPO4 · 2H2O)) — mineral

Variscite in Matrix

Variscite (AlPO4 · 2H2O)

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

Citrine Quartz

Silicon Dioxide (SiO2) with iron impurities

Precious Opal in Matrix (Hydrated Silica (SiO2·nH2O)) — mineral

Precious Opal in Matrix

Hydrated Silica (SiO2·nH2O)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Pearl (Calcium carbonate (CaCO3) - Aragonite/Calcite variety) — mineral

Pearl

Calcium carbonate (CaCO3) - Aragonite/Calcite variety

Chert / River Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Rhodochrosite (Rhodochrosite, Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Rhodochrosite, Manganese Carbonate (MnCO3)

Howlite (Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)) — mineral

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Chert (and Limestone Pebbles) (Silicon Dioxide (SiO2) / Sedimentary Microcrystalline Quartz) — sedimentary

Chert (and Limestone Pebbles)

Silicon Dioxide (SiO2) / Sedimentary Microcrystalline Quartz

Chert (often called Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (often called Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (specifically Flint or Common Chert) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (specifically Flint or Common Chert)

Chert (Cryptocrystalline Silica, SiO2)

Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Citrine (Silicon Dioxide (SiO2)) — mineral

Citrine

Silicon Dioxide (SiO2)