Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Learn about Organic Gemstone in the encyclopedia

Jet

Jet

Sapropel

Sapropel

Red Garnet

Red Garnet

Bituminous Shale

Bituminous Shale

Black Shale

Black Shale

Petrified Wood

Petrified Wood

Amber

Amber

Peat

Peat

Oil Shale

Oil Shale

Pearl

Pearl

Lizard Skin Jasper

Lizard Skin Jasper

Rhodonite

Rhodonite

Petrified Wood (Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal replacing organic matter)

Moss Agate (Silicon Dioxide (SiO2) with inclusions) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions

Ironstone Concretion (Limonite/Goethite) (Iron oxide concretion (contains FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Limonite/Goethite)

Iron oxide concretion (contains FeO(OH)·nH2O)

Tree Agate (Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)) — mineral

Tree Agate

Dendritic Agate (Silicon Dioxide, SiO2 with chlorite inclusions)

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 (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Moss Agate (Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions) — mineral

Moss Agate

Silicon Dioxide (SiO2) with Chlorite/Oxide inclusions

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Limestone (Tufa/Travertine) (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone (Tufa/Travertine)

Sedimentary Calcium Carbonate (CaCO3)

Concretion (Septarian Concretion (Fragmentary)) — sedimentary

Concretion

Septarian Concretion (Fragmentary)

Black Dolomite (Bituminous Dolomite (CaMg(CO3)2)) — sedimentary

Black Dolomite

Bituminous Dolomite (CaMg(CO3)2)

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

Chert / River Cobble

Microcrystalline Quartz (SiO2)

Travertine (Terrestrial Sedimentary Limestone (CaCO3)) — sedimentary

Travertine

Terrestrial Sedimentary Limestone (CaCO3)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Glauconitic Sandstone (Greensand) (Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)) — sedimentary

Glauconitic Sandstone (Greensand)

Glauconitic Sandstone (Iron-potassium phyllosilicate mineral: (K,Na)(Fe3+,Al,Mg)2(Si,Al)4O10(OH)2)

Chert (variously known as Flint) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (variously known as Flint)

Microcrystalline quartz (SiO2)

Red Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Nodule) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Chert (with Limestone matrix) (Silicon dioxide (SiO2)) — sedimentary

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Chert (Jasper variation) (Chert (Microcrystalline Silicon Dioxide, SiO2)) — sedimentary

Chert (Jasper variation)

Chert (Microcrystalline Silicon Dioxide, SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Chert (Yellow Jasper) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Chert (and Chalcedony) (Silicon Dioxide (SiO2)) — sedimentary

Chert (and Chalcedony)

Silicon Dioxide (SiO2)

Chert (Beach Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Beach Pebble)

Microcrystalline Quartz (SiO2)

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

Chert (often called Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert / Jasper

Silicon Dioxide (SiO2)

Fossilized Bone (Permineralized Vertebrate Fossil) — sedimentary

Fossilized Bone

Permineralized Vertebrate Fossil

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

Chert Pebble

Chert (Silicon Dioxide, SiO2)

Chert (often called Flint in various colors) (Silicon Dioxide (SiO2)) — sedimentary

Chert (often called Flint in various colors)

Silicon Dioxide (SiO2)

Chert (Green variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Green variety)

Silicon Dioxide (SiO2)

Graphite (Graphite (Native Carbon), Formula: C) — Metamorphic

Graphite

Graphite (Native Carbon), Formula: C

Graphite (Graphite (Carbon, C)) — metamorphic

Graphite

Graphite (Carbon, C)

Micro-crystalline Quartz Pebble (Chert) (Silicon dioxide (SiO2)) — sedimentary

Micro-crystalline Quartz Pebble (Chert)

Silicon dioxide (SiO2)

Chert (Jasper/Flint variety) (Silicon dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Jasper/Flint variety)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Fossiliferous Limestone (Coquina) (Calcite (CaCO3) with Bioclastic inclusions) — sedimentary

Fossiliferous Limestone (Coquina)

Calcite (CaCO3) with Bioclastic inclusions

Chert (Iron-stained) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline Quartz (SiO2)

Fossil Coral (Cnidaria Anthozoa (Fossilized)) — sedimentary

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)