Rock Identifier

Category

Organic Material

Browse organic material specimens identified by the Rock Identifier community.

Learn about Organic Material in the encyclopedia

Peat

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Jet

Oil Shale

Pearl

Lizard Skin Jasper

Dunite

Opalized Wood

Gravel / Limestone Fragment (Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock) — sedimentary

Gravel / Limestone Fragment

Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock

Fossil Shark Tooth (Carcharodon sp. (likely Otodus or similar Lamniformes order)) — sedimentary

Fossil Shark Tooth

Carcharodon sp. (likely Otodus or similar Lamniformes order)

Fossiliferous Sandstone with Plant Remains (Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)) — sedimentary

Fossiliferous Sandstone with Plant Remains

Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)

Coarse Sand or Fine Gravel (Detrital Sedimentary Fragments (mostly SiO2)) — sedimentary

Coarse Sand or Fine Gravel

Detrital Sedimentary Fragments (mostly SiO2)

Sedimentary Rock (Limestone or Siltstone pebble) (Sedimentary rock fragment) — sedimentary

Sedimentary Rock (Limestone or Siltstone pebble)

Sedimentary rock fragment

Quartz-veined Limestone (Sedimentary limestone with quartz/calcite veinlets) — sedimentary

Quartz-veined Limestone

Sedimentary limestone with quartz/calcite veinlets

Fossil bivalve shell (Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized) — fossil

Fossil bivalve shell

Ribbed pectinid or related bivalve; originally calcite/aragonite (CaCO₃), likely partially mineralized

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

Chert (Flint)

Silicon dioxide (SiO2)

Chert (Jasper/Chalcedony mix) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper/Chalcedony mix)

Microcrystalline Quartz (SiO2)

Chert Nodules in Limestone (Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)) — sedimentary

Chert Nodules in Limestone

Cryptocrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Anthracite Coal (Carbon (with trace impurities)) — sedimentary

Anthracite Coal

Carbon (with trace impurities)

Limestone with Gastropod Fossil (Sedimentary Calcium Carbonate (CaCO3) with Gastropoda inclusion) — fossil

Limestone with Gastropod Fossil

Sedimentary Calcium Carbonate (CaCO3) with Gastropoda inclusion

Tumbled coral fragment (likely white calcitic coral) (Calcium carbonate, primarily aragonite or calcite (CaCO₃); exact coral genus cannot be determined from the image) — fossil

Tumbled coral fragment (likely white calcitic coral)

Calcium carbonate, primarily aragonite or calcite (CaCO₃); exact coral genus cannot be determined from the image

Bamboo Leaf Jasper (Silicified Siltstone or Jasper (SiO2)) — sedimentary

Bamboo Leaf Jasper

Silicified Siltstone or Jasper (SiO2)

Fossilized coral or silicified organic limestone (Likely fossil coral (Scleractinia/Tabulata) replaced or cemented by calcite and silica; exact identification requires close examination) — fossil

Fossilized coral or silicified organic limestone

Likely fossil coral (Scleractinia/Tabulata) replaced or cemented by calcite and silica; exact identification requires close examination

Fossil Shark Tooth (Chondrichthyes (class); likely Lamniformes (order) fossilized in Apatite/Hydroxyapatite) — fossil

Fossil Shark Tooth

Chondrichthyes (class); likely Lamniformes (order) fossilized in Apatite/Hydroxyapatite

Chert (Common Opal/Jasper mix) (Silicon Dioxide (SiO2) with impurities) — sedimentary

Chert (Common Opal/Jasper mix)

Silicon Dioxide (SiO2) with impurities

Fossilized Shell (Invertebrate fossil (Bivalvia or Brachiopoda)) — fossil

Fossilized Shell

Invertebrate fossil (Bivalvia or Brachiopoda)

Chert Nodules (with Flint core) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Nodules (with Flint core)

Microcrystalline Quartz (SiO2)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Onyx (Black) and Mother of Pearl Inlay (Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl) — mineral

Onyx (Black) and Mother of Pearl Inlay

Silicon Dioxide (SiO2) for Onyx; Aragonite (CaCO3) for Mother of Pearl

Fossil bivalve shell (Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features) — fossil

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Petrified Wood (Petrified Wood (Silicified Wood)) — fossil

Petrified Wood

Petrified Wood (Silicified Wood)

Petrified Wood (Silicified wood (SiO2)) — fossil

Petrified Wood

Silicified wood (SiO2)

Mother of Pearl (Nacre) / Shell Fragment (Biogenic Calcium Carbonate (Aragonite and Conchiolin)) — fossil

Mother of Pearl (Nacre) / Shell Fragment

Biogenic Calcium Carbonate (Aragonite and Conchiolin)

Fossiliferous Limestone (Calcite (CaCO3) matrix with biogenic fragments) — sedimentary

Fossiliferous Limestone

Calcite (CaCO3) matrix with biogenic fragments

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (and Fossilized Brachiopod shell) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Chert Pebble (Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Cryptocrystalline Quartz (SiO2)

Fossiliferous Limestone (Calcium Carbonate (CaCO3) with fossil inclusions) — sedimentary

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with fossil inclusions

Chert (likely flint), possibly chalcedony-rich (Microcrystalline quartz, SiO₂ (quartz/chalcedony)) — sedimentary

Chert (likely flint), possibly chalcedony-rich

Microcrystalline quartz, SiO₂ (quartz/chalcedony)

Sedimentary Rock with Crafts (Pet Rock) (Sedimentary rock decorated with synthetic materials) — sedimentary

Sedimentary Rock with Crafts (Pet Rock)

Sedimentary rock decorated with synthetic materials

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (primarily Quartz / Chalcedony: SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Quartz / Chalcedony: SiO2)

Travertine (Travertine (a terrestrial form of Limestone, CaCO3)) — sedimentary

Travertine

Travertine (a terrestrial form of Limestone, CaCO3)

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

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Likely coal (possibly anthracite) (Coal, composed chiefly of carbon-rich organic matter; rank cannot be confirmed from the photograph) — sedimentary

Likely coal (possibly anthracite)

Coal, composed chiefly of carbon-rich organic matter; rank cannot be confirmed from the photograph

Polished green moss agate cabochon (Moss agate: microcrystalline quartz (SiO₂) with included chlorite/actinolite or iron-manganese minerals) — mineral

Polished green moss agate cabochon

Moss agate: microcrystalline quartz (SiO₂) with included chlorite/actinolite or iron-manganese minerals