Rock Identifier

Category

Organic (Biological Specimen)

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

Anthracite Coal (Anthracite) — metamorphic

Anthracite Coal

Anthracite

Septarian Nodule (Septarian Concretion (Calcite, Aragonite, and Limestone)) — sedimentary

Septarian Nodule

Septarian Concretion (Calcite, Aragonite, and Limestone)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Banded Chert (with Quartz Vein) (Microcrystalline Silica (SiO2)) — sedimentary

Banded Chert (with Quartz Vein)

Microcrystalline Silica (SiO2)

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

Chert (Green variety)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Amber (specifically Cherry Amber) (Succinite (with the chemical formula C10H16O)) — Organic Gemstone (not a mineral)

Amber (specifically Cherry Amber)

Succinite (with the chemical formula C10H16O)

Organic Gemstone (not a mineral)

Red Sandstone with Reduction Spot (Quartzose Sandstone with a Leach/Reduction Spot) — sedimentary

Red Sandstone with Reduction Spot

Quartzose Sandstone with a Leach/Reduction Spot

Veined Limestone (Sedimentary Calcite-Veined Rock (CaCO3)) — sedimentary

Veined Limestone

Sedimentary Calcite-Veined Rock (CaCO3)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Chert (and its variety Flint) (Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz) — sedimentary

Chert (and its variety Flint)

Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz

Banded Chert (or River Jasper) (Microcrystalline Quartz (SiO2) with iron oxide impurities) — sedimentary

Banded Chert (or River Jasper)

Microcrystalline Quartz (SiO2) with iron oxide impurities

Red Jasper (Jasper (Silicon Dioxide with Iron inclusions - SiO2)) — Sedimentary/Metamorphic

Red Jasper

Jasper (Silicon Dioxide with Iron inclusions - SiO2)

Sedimentary/Metamorphic

Red Jasper (Silicon Dioxide (SiO2) with Hematite impurities) — sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Travertine (often colloquially called Tufa) (Chemical Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Travertine (often colloquially called Tufa)

Chemical Sedimentary Calcium Carbonate (CaCO3)

Petrified Wood (Silicified Wood (Silicon Dioxide - SiO2)) — fossil

Petrified Wood

Silicified Wood (Silicon Dioxide - SiO2)

Amber (Cherry or Red variety) (Succinite (with various trace amounts of organic compounds)) — Organic Gemstone (not a rock)

Amber (Cherry or Red variety)

Succinite (with various trace amounts of organic compounds)

Organic Gemstone (not a rock)

Bituminous Coal (Organic-rich sedimentary rock (Complex hydrocarbons)) — sedimentary

Bituminous Coal

Organic-rich sedimentary rock (Complex hydrocarbons)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Anthracite Coal (Anthracite (Carbon-rich metamorphic coal)) — metamorphic

Anthracite Coal

Anthracite (Carbon-rich metamorphic coal)

Chert (Hag Stone / Hole Stone) (Chert (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Chert (Hag Stone / Hole Stone)

Chert (Cryptocrystalline variety of Quartz, SiO2)

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

Jasper

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

Amber (Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O) — Organic mineraloid

Amber

Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O

Organic mineraloid

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

Fossilized Coral (Petoskey Stone / Favosites)

Hexagonaria percarinata / Favosites sp. (Calcite, CaCO3)

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

Tufa (Calcareous Tufa)

Calcareous Tufa (CaCO3)

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

Chert (Iron-Stained)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Orange Calcite (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite

Calcium Carbonate (CaCO3)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Petoskey Stone (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Fossilized Horn Coral (Rugosa (Tetracoralla)) — fossil

Fossilized Horn Coral

Rugosa (Tetracoralla)

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

Chert (variations include Flint or Jasper)

Silicon Dioxide (SiO2)

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

Chert (Jasper variation)

Chert (SiO2)

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

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Chert (Cryptocrystalline variety of Quartz, SiO2)

Fossiliferous Limestone / Petoskey Stone (Coral Fossil) (Hexagonaria percarinata / Calcite (CaCO3)) — fossil

Fossiliferous Limestone / Petoskey Stone (Coral Fossil)

Hexagonaria percarinata / Calcite (CaCO3)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — fossil

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

Fossil Coral (Phylum Cnidaria / Rugosa or Tabulata) — fossil

Fossil Coral

Phylum Cnidaria / Rugosa or Tabulata

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified wood (Quartz/Chalcedony replacement of organic matter)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of organic matter)

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

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

Ironstone Concretion (Limonite/Hematite Nodules) (Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)) — sedimentary

Ironstone Concretion (Limonite/Hematite Nodules)

Ironstone (principally Limonite FeO(OH)·nH2O or Hematite Fe2O3 mixed with silica/clay)