Rock Identifier

Category

Organic Gemstone

Browse organic gemstone specimens identified by the Rock Identifier community.

Learn about Organic Gemstone in the encyclopedia

Jet

Sapropel

Red Garnet

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Oil Shale

Peat

Pearl

Lizard Skin Jasper

Sunstone

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Pyritized Ammonite (Ammonitida (replaced by Iron Disulfide, FeS2)) — sedimentary

Pyritized Ammonite

Ammonitida (replaced by Iron Disulfide, FeS2)

Fossiliferous Limestone (Bioclastic Limestone (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone

Bioclastic Limestone (Calcium Carbonate, CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Weathered iron-rich rock, likely ferruginous sandstone or lateritic concretion (Iron-oxide–cemented sandstone; commonly dominated by quartz (SiO₂), goethite (FeO(OH)) and hematite (Fe₂O₃)) — sedimentary

Weathered iron-rich rock, likely ferruginous sandstone or lateritic concretion

Iron-oxide–cemented sandstone; commonly dominated by quartz (SiO₂), goethite (FeO(OH)) and hematite (Fe₂O₃)

Graphitic schist (probable) (Graphite-bearing mica schist; chiefly quartz, mica, and graphite) — metamorphic

Graphitic schist (probable)

Graphite-bearing mica schist; chiefly quartz, mica, and graphite

Tumbled moss agate (Chalcedony (microcrystalline quartz, SiO₂) with moss-like inclusions) — mineral

Tumbled moss agate

Chalcedony (microcrystalline quartz, SiO₂) with moss-like inclusions

Concretion (Septarian or Siderite Concretion) — sedimentary

Concretion

Septarian or Siderite Concretion

Chert Concretion (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert Concretion

Sedimentary Cryptocrystalline Quartz (SiO2)

Amber (Succinite (Fossilized Tree Resin)) — fossil

Amber

Succinite (Fossilized Tree Resin)

Banded Siltstone Pebble (Siltstone (primarily SiO2, Al2O3, Fe2O3)) — sedimentary

Banded Siltstone Pebble

Siltstone (primarily SiO2, Al2O3, Fe2O3)

Desert Rose Fragment (Atypical) / Weathered Chert (Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy) — sedimentary

Desert Rose Fragment (Atypical) / Weathered Chert

Silicon Dioxide (SiO2) or Barium Sulfate (BaSO4) depending on exact mineralogy

Amber (Succinates (C10H16O)) — mineraloid

Amber

Succinates (C10H16O)

Amber (Succinite (Resinite), C10-H16-O) — mineral

Amber

Succinite (Resinite), C10-H16-O

Fossiliferous Limestone with Fossil Fragment (Fossiliferous Limestone (CaCO3 with organic remains)) — fossil

Fossiliferous Limestone with Fossil Fragment

Fossiliferous Limestone (CaCO3 with organic remains)

Jasper (Silicon dioxide (Quartz variety), SiO2) — sedimentary

Jasper

Silicon dioxide (Quartz variety), SiO2

Fossiliferous Sedimentary Rock (Sedimentary Rock with Invertebrate Fossil Imprint) — fossil

Fossiliferous Sedimentary Rock

Sedimentary Rock with Invertebrate Fossil Imprint

Fossilized Bone (Permineralized Vertebrate Bone) — fossil

Fossilized Bone

Permineralized Vertebrate Bone

Fossiliferous Limestone (Biogenic Sedimentary Rock / CaCO3 with fossil fragments) — sedimentary

Fossiliferous Limestone

Biogenic Sedimentary Rock / CaCO3 with fossil fragments

Fossil Shell (Brachiopod or Mollusk fossil) — fossil

Fossil Shell

Brachiopod or Mollusk fossil

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

Chert (often called Flint or Jasper)

Microcrystalline quartz (SiO2)

Shungite (Non-crystalline carbon (C)) — mineral

Shungite

Non-crystalline carbon (C)

Banded Limestone (Calcareous sedimentary rock (CaCO3)) — sedimentary

Banded Limestone

Calcareous sedimentary rock (CaCO3)

Chert (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert

Sedimentary Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (specifically Cryptocrystalline Quartz) (Silicon dioxide (SiO2)) — sedimentary

Chert (specifically Cryptocrystalline Quartz)

Silicon dioxide (SiO2)

Fossil Shark Tooth (Otodus sp. or Carcharocles sp. (likely fossilized Chondrichthyes)) — fossil

Fossil Shark Tooth

Otodus sp. or Carcharocles sp. (likely fossilized Chondrichthyes)

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

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Chert (Jasper) (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper)

Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (Fossiliferous Calcite (CaCO3)) — sedimentary

Fossiliferous Limestone

Fossiliferous Calcite (CaCO3)

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

Chert (Flint)

Microcrystalline silica (SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Chert (or Chalcedony) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (or Chalcedony)

Microcrystalline Quartz (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Chert (White/Gray variety) (Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)) — sedimentary

Chert (White/Gray variety)

Silicon Dioxide (SiO2 / Cryptocrystalline Quartz)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Flint)

Chert (SiO2)

Chert (Chalcedony/Common Opal) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Common Opal)

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Jasper Agate (Silicon dioxide (SiO2)) — mineral

Jasper Agate

Silicon dioxide (SiO2)

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

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)