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

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

Chert (Jasper/Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (often called Flint or Jasper if reddish)

Microcrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Chert (Flint)

Chert (Silicon Dioxide, SiO2)

Chert (Jasper variation) (Chert (SiO2)) — sedimentary

Chert (Jasper variation)

Chert (SiO2)

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

Chert (Nodular Chert)

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Chert Pebble (Jasper/Quartz variety)

Microcrystalline Quartz (SiO2)

Rhodochrosite (Manganese Carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese Carbonate (MnCO3)

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

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

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

Sunstone

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

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

Prehnite

Ca2Al(AlSi3O10)(OH)2

Pearl (as a biogenic mineral/gemstone) (Calcium Carbonate (mostly Aragonite), CaCO3) — mineral

Pearl (as a biogenic mineral/gemstone)

Calcium Carbonate (mostly Aragonite), CaCO3

Chert / Jasper (Silicon Dioxide (SiO2)) — sedimentary

Chert / Jasper

Silicon Dioxide (SiO2)

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

Sunstone (Heliolite)

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

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

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Chert (often associated with Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often associated with Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Red Jasper

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

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

Chert (Flint variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (and/or River Pebble) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (and/or River Pebble)

Microcrystalline quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Green Quartz (Prasiolite/Adventurine) (Silicon Dioxide with inclusions (SiO2)) — mineral

Green Quartz (Prasiolite/Adventurine)

Silicon Dioxide with inclusions (SiO2)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Zebra Marble (Metamorphosed Limestone (Recrystallized Calcite)) — metamorphic

Zebra Marble

Metamorphosed Limestone (Recrystallized Calcite)

Sunstone (Oregon Sunstone) (Labradorite (Feldspar variety) - (Ca, Na)(Al, Si)4O8) — mineral

Sunstone (Oregon Sunstone)

Labradorite (Feldspar variety) - (Ca, Na)(Al, Si)4O8

Travertine (Tufa) (Chemical Sedimentary Rock / Travertine (CaCO3)) — sedimentary

Travertine (Tufa)

Chemical Sedimentary Rock / Travertine (CaCO3)

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

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

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

Turquoise

Hydrated phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)

Chert (often called Flint) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint)

Cryptocrystalline Quartz (SiO2)

Rhodochrosite (Manganese carbonate (MnCO3)) — mineral

Rhodochrosite

Manganese carbonate (MnCO3)

Tahitian Pearl (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Tahitian Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Chert (Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Clear Quartz / Rock Crystal (Silicon Dioxide (SiO2)) — mineral

Clear Quartz / Rock Crystal

Silicon Dioxide (SiO2)

Moss Agate (Chalcedony (SiO2) with inclusions of manganese or iron oxides) — mineral

Moss Agate

Chalcedony (SiO2) with inclusions of manganese or iron oxides

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

Petrified Wood

Silicified Wood (primarily 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)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

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