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

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

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

Chert Nodule (Flint)

Chert (Silicon Dioxide, SiO2)

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

Chert (Flint)

Chert (Cryptocrystalline Silicon Dioxide, SiO2)

Chert (concretionary/nodular variant) (Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions) — sedimentary

Chert (concretionary/nodular variant)

Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions

Chert with Iron Staining (Microcrystalline Quartz (SiO2)) — sedimentary

Chert with Iron Staining

Microcrystalline Quartz (SiO2)

Chert (and Jasper pebble) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (and Jasper pebble)

Microcrystalline Silica (SiO2)

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

Petrified Wood

Silicified Wood (primarily Chalcedony or Quartz, SiO2)

mineral/sedimentary

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

Chert (Yellow Jasper/Agatized Chert)

Microcrystalline Quartz (SiO2)

Chert (Tan/Yellow variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Tan/Yellow variety)

Microcrystalline Quartz (SiO2)

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

Petrified Wood

Silicified Wood (primarily SiO2)

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

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Chert (with small quartz vug) (Chert (SiO2)) — sedimentary

Chert (with small quartz vug)

Chert (SiO2)

Chert (often called Flint) (Microcrystalline to cryptocrystalline quartz (SiO2)) — sedimentary

Chert (often called Flint)

Microcrystalline to cryptocrystalline quartz (SiO2)

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

Chert (Jasper)

Microcrystalline quartz (SiO2)

Chert (varietal: Flint/Jasper mix) (Hydrous Silica (SiO2)) — sedimentary

Chert (varietal: Flint/Jasper mix)

Hydrous Silica (SiO2)

Chert (containing Flint and Calcareous inclusions) (Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities) — sedimentary

Chert (containing Flint and Calcareous inclusions)

Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) impurities

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (often called Flint or River Stone) (Microcrystalline alpha-quartz (SiO2)) — sedimentary

Chert (often called Flint or River Stone)

Microcrystalline alpha-quartz (SiO2)

Chert (Smooth River Siltstone/Basalt variant) (Silicon dioxide (SiO2) / Microcrystalline Quartz) — sedimentary

Chert (Smooth River Siltstone/Basalt variant)

Silicon dioxide (SiO2) / Microcrystalline Quartz

Chert / Flint Nodules (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert / Flint Nodules

Chert (Cryptocrystalline variety of Quartz, SiO2)

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

Green Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (White Chert / Flint) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

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

Moss Agate

Silicon Dioxide with inclusions (SiO2 + impurities)

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

Tahitian Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Moss Agate (Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide) — mineral

Moss Agate

Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxide

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Ironstone Concretion (Siderite or Hematite Concretion) — sedimentary

Ironstone Concretion

Siderite or Hematite Concretion

Limestone (Calcium carbonate (CaCO3)) — sedimentary

Limestone

Calcium carbonate (CaCO3)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Petrified Wood

Silicified Wood (primarily SiO2)

Amber (Succinite (Fossilized Tree Resin)) — gemstone

Amber

Succinite (Fossilized Tree Resin)

Shale (Shale (Fine-grained clastic sedimentary rock)) — sedimentary

Shale

Shale (Fine-grained clastic sedimentary rock)

Lignite (Brown Coal) (Humic Lignite (Carbonaceous sedimentary rock)) — sedimentary

Lignite (Brown Coal)

Humic Lignite (Carbonaceous sedimentary rock)

Glauconite (Green Sandstone) (Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2) — sedimentary

Glauconite (Green Sandstone)

Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

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

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (primarily Quartz/Chalcedony, SiO2)) — fossil

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Fossiliferous Limestone with Rugose Coral (Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)) — sedimentary

Fossiliferous Limestone with Rugose Coral

Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)

Coral Fossil (Agatized Coral or Petoskey Stone) (Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)) — Sedimentary/Fossil

Coral Fossil (Agatized Coral or Petoskey Stone)

Hexagonaria percarinata (if Petoskey) or generally Scleractinia (Agatized Coral)

Sedimentary/Fossil

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

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)