Rock Identifier

Category

Organic Specimen (Fossil)

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

Learn about Organic Specimen (Fossil) in the encyclopedia

Petrified Wood

Amber

Jet

Opalized Wood

Petrified Wood (Silicified wood (primarily quartz, SiO2)) — fossil

Petrified Wood

Silicified wood (primarily quartz, SiO2)

Petrified Wood (Silicified Wood / Xylopal (SiO2)) — fossil

Petrified Wood

Silicified Wood / Xylopal (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

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

Flint / Chert

Silicon Dioxide (SiO2)

Sandstone (with ripple marks) (Arenite (SiO2 primarily)) — sedimentary

Sandstone (with ripple marks)

Arenite (SiO2 primarily)

Amber (Succinite (approximate formula C10H16O)) — mineraloid

Amber

Succinite (approximate formula C10H16O)

Limestone (River or Sea Cobble) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (River or Sea Cobble)

Calcium Carbonate (CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Petrified Palm Wood (Palmoxylon) — fossil

Petrified Palm Wood

Palmoxylon

Petrified Wood (Fossilized Wood (SiO2 replacing organic matter)) — fossil

Petrified Wood

Fossilized Wood (SiO2 replacing organic matter)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2 / Quartz pseudomorph after wood)) — fossil

Petrified Wood

Silicified Wood (SiO2 / Quartz pseudomorph after wood)

Limestone with Fossil Fragments (Bioclastic Limestone (CaCO3)) — sedimentary

Limestone with Fossil Fragments

Bioclastic Limestone (CaCO3)

Orbicular granite (likely rapakivi-type granite) (Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende) — igneous

Orbicular granite (likely rapakivi-type granite)

Granite; chiefly quartz, alkali feldspar, plagioclase, and biotite/hornblende

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

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Fossil Coral and Quartz Pebble (Fossilized Anthozoa / Silicon Dioxide (Quartz)) — sedimentary

Fossil Coral and Quartz Pebble

Fossilized Anthozoa / Silicon Dioxide (Quartz)

Petoskey Stone / Fossilized Coral (Hexagonaria percarinata) — fossil

Petoskey Stone / Fossilized Coral

Hexagonaria percarinata

Shale (or Mudstone) (Siltstone/Argillite (composed mainly of clay and silt-sized particles)) — sedimentary

Shale (or Mudstone)

Siltstone/Argillite (composed mainly of clay and silt-sized particles)

Coral Fossil (Petrified Coral) (Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)) — sedimentary

Coral Fossil (Petrified Coral)

Scleractinia (Order) - Calcified Fossil Skeleton (CaCO3)

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

Petrified Wood

Silicified wood (primarily SiO2 - Silicon Dioxide)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Coal (likely Bituminous or Lignite) (Organic Sedimentary Rock (Carbonaceous)) — sedimentary

Coal (likely Bituminous or Lignite)

Organic Sedimentary Rock (Carbonaceous)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Iron Oxide cement)

Ironstone Concretion (Ironstone Gourd) (Limonite/Goethite Concretion (FeOO(H))) — sedimentary

Ironstone Concretion (Ironstone Gourd)

Limonite/Goethite Concretion (FeOO(H))

Coquina / Shelly Sandstone (Calcareous Sandstone / Coquina) — sedimentary

Coquina / Shelly Sandstone

Calcareous Sandstone / Coquina

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Limestone with Secondary Mineralization (Calcium Carbonate (CaCO3)) — sedimentary

Limestone with Secondary Mineralization

Calcium Carbonate (CaCO3)

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

Limestone (with potential fossil inclusions)

Calcium Carbonate (CaCO3)

Calcite-rich limestone (Limestone, primarily calcite (CaCO₃), possibly fossiliferous or dolomitic) — sedimentary

Calcite-rich limestone

Limestone, primarily calcite (CaCO₃), possibly fossiliferous or dolomitic

Sandstone (Micaceous) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (Micaceous)

Arenite (composed primarily of SiO2)

Fossilized Shark Tooth in Matrix (Otodus obliquus (Chondrichthyes: Lamniformes)) — fossil

Fossilized Shark Tooth in Matrix

Otodus obliquus (Chondrichthyes: Lamniformes)

Bituminous Coal (with Anthracite or Vitrinite inclusion) (Organic-rich Sedimentary Rock (Carboniferous classification)) — sedimentary

Bituminous Coal (with Anthracite or Vitrinite inclusion)

Organic-rich Sedimentary Rock (Carboniferous classification)

Amber (Succinite (Resin C10H16O)) — mineral

Amber

Succinite (Resin C10H16O)

Fossiliferous Limestone (Hash) (Bioclastic Grainstone / Calcarenite) — fossil

Fossiliferous Limestone (Hash)

Bioclastic Grainstone / Calcarenite

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

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

Lignite (Brown Coal)

Humic Lignite (Carbonaceous sedimentary rock)

Mosasaur Tooth (Mosasauridae (likely Prognathodon or Mosasaurus species)) — fossil

Mosasaur Tooth

Mosasauridae (likely Prognathodon or Mosasaurus species)

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

Chert (River Pebble)

Silicon Dioxide (SiO2)

Amber (Rough) (Amber (Fossilized Tree Resin, succinite)) — mineral

Amber (Rough)

Amber (Fossilized Tree Resin, succinite)