Rock Identifier

Category

Organic (Anthropogenic)

Browse organic (anthropogenic) specimens identified by the Rock Identifier community.

Learn about Organic (Anthropogenic) in the encyclopedia

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Jet

Peat

Oil Shale

Pearl

Lizard Skin Jasper

Opalized Wood

Coral Rock

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

Moss Agate

Chalcedony (Silicon Dioxide with inclusions) - SiO2

Limestone (Weathered) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (Weathered)

Calcium Carbonate (CaCO3)

Fossilized Echinoid / Sea Urchin Internal Mold (Echinoidea internal cast (steinkern)) — fossil

Fossilized Echinoid / Sea Urchin Internal Mold

Echinoidea internal cast (steinkern)

Agatized Dinosaur Bone (Permineralized Dinosaur Bone (Silicified/Agatized Bone)) — fossil

Agatized Dinosaur Bone

Permineralized Dinosaur Bone (Silicified/Agatized Bone)

Fossilized Coral (Petoskey Stone / Favosites) (Hexagonaria percarinata / Favosites sp. (Calcite, CaCO3)) — fossil

Fossilized Coral (Petoskey Stone / Favosites)

Hexagonaria percarinata / Favosites sp. (Calcite, CaCO3)

Fossil Coral (Petoskey / Horn Coral Sliced Button) (Scleractinia / Rugosa (Silurian-Devonian Anthozoa)) — fossil

Fossil Coral (Petoskey / Horn Coral Sliced Button)

Scleractinia / Rugosa (Silurian-Devonian Anthozoa)

Jasper (Mookaite variety likely) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Mookaite variety likely)

Silicon Dioxide (SiO2) with iron oxide inclusions

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

Jasper

Silicon Dioxide (SiO2) with iron oxide impurities

Banded Chert (Ironstone/Jasper) (Cryptocrystalline Quartz (SiO2) with Iron Oxides) — sedimentary

Banded Chert (Ironstone/Jasper)

Cryptocrystalline Quartz (SiO2) with Iron Oxides

Septarian Nodule (Dragon Stone) (Septarian Concretion (CaCO3 with Siderite and Calcite)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian Concretion (CaCO3 with Siderite and Calcite)

Chert (variations include Flint or Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

Jasper (Agate/Jasper (Microcrystalline Quartz, SiO2)) — sedimentary

Jasper

Agate/Jasper (Microcrystalline Quartz, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Septarian Nodule or Mud Crack Fossil (Septarian Nodule (Concretion)) — sedimentary

Septarian Nodule or Mud Crack Fossil

Septarian Nodule (Concretion)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Septarian Nodule (Dragon Stone) (Septarian Geode (CaCO3 + Mg + Fe)) — sedimentary

Septarian Nodule (Dragon Stone)

Septarian Geode (CaCO3 + Mg + Fe)

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

Chert (Jasper variation)

Chert (SiO2)

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

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

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

Tufa (Calcareous Tufa)

Calcareous Tufa (CaCO3)

Petrified Wood (Silicified wood (Quartz/Chalcedony/SiO2)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony/SiO2)

Chert (Brecciated or Veined) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Brecciated or Veined)

Silicon Dioxide (SiO2)

Chert (Iron-Stained) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Seashell Fossil (Invertebrate fossil (phylum Mollusca)) — fossil

Seashell Fossil

Invertebrate fossil (phylum Mollusca)

Limestone Pebble (Calcite-rich Sedimentary Rock (CaCO3)) — sedimentary

Limestone Pebble

Calcite-rich Sedimentary Rock (CaCO3)

Petrified Wood (Silicified wood / Xylopal) — fossil

Petrified Wood

Silicified wood / Xylopal

Agate (Geode/Nodule) (Chalcedony (cryptocrystalline silica, SiO2)) — sedimentary

Agate (Geode/Nodule)

Chalcedony (cryptocrystalline silica, SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Fossilized Wood (with Coal and Limonite) (Petrified Wood (Silicified or Carbonized Flora)) — sedimentary

Fossilized Wood (with Coal and Limonite)

Petrified Wood (Silicified or Carbonized Flora)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (primarily Chalcedony or Quartz, SiO2)) — sedimentary

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

Petrified Wood (Agatized/Silicified Wood) (Silicified Wood / Chalcedony (SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood / Chalcedony (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Chert (Iron-stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Jasper (Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)) — sedimentary

Jasper

Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)

Chert (Chalcedony/Agate) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)