Rock Identifier

Category

Organic Structure (Not A Rock)

Browse organic structure (not a rock) specimens identified by the Rock Identifier community.

Learn about Organic Structure (Not A Rock) in the encyclopedia

Bituminous Shale

Bituminous Shale

Black Shale

Oil Shale

Petrified Wood

Crocodile Jasper

Crocodile Jasper

Opalized Wood

Rock Salt

Rock Gypsum

Coral Rock

Asphalt Rock

Calc-Silicate Rock

Calc-Silicate Rock

Talc-carbonate Rock

Talc-carbonate Rock

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert (Nodule)

Microcrystalline Quartz (SiO2)

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

Fossiliferous Limestone

Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)

Pyrite in Slate (Iron Sulfide (FeS2) in Slate host matrix) — metamorphic

Pyrite in Slate

Iron Sulfide (FeS2) in Slate host matrix

Travertine (Tufa) (Chemical Sedimentary Rock / Travertine (CaCO3)) — sedimentary

Travertine (Tufa)

Chemical Sedimentary Rock / Travertine (CaCO3)

Fossilized Coprolite (Coprolite (fossilized feces)) — sedimentary

Fossilized Coprolite

Coprolite (fossilized feces)

Chert (and/or River Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (and/or River Pebble)

Microcrystalline silica (SiO2)

Dendritic jasper/chalcedony (Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites) — mineral

Dendritic jasper/chalcedony

Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites

Chert (Jasper) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Jasper)

Sedimentary Cryptocrystalline Quartz (SiO2)

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock transitioned to metamorphic)

Possible fossilized shell or coral fragment (Indeterminate biogenic carbonate, likely calcite (CaCO₃)) — fossil

Possible fossilized shell or coral fragment

Indeterminate biogenic carbonate, likely calcite (CaCO₃)

Lapis Lazuli (Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)) — metamorphic

Lapis Lazuli

Lapis Lazuli (Mineral composition: Lazurite (Na,Ca)8(AlSiO4)6(SO4,S,Cl,OH)2, Calcite, and Pyrite)

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

Petrified Wood

Silicified wood (Quartz/Chalcedony - SiO2)

Chert (Quartz Variety) (Microcrystalline / Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Quartz Variety)

Microcrystalline / Cryptocrystalline Quartz (SiO2)

Tree Agate (Silicon Dioxide (SiO2) with Dendritic Inclusions) — Mineral

Tree Agate

Silicon Dioxide (SiO2) with Dendritic Inclusions

Ferruginous Sandstone (Ironstone) (Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)) — sedimentary

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Tumbled banded agate (likely chalcedony) (Microcrystalline quartz, SiO₂; probable banded chalcedony/agate) — mineral

Tumbled banded agate (likely chalcedony)

Microcrystalline quartz, SiO₂; probable banded chalcedony/agate

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

Fossilized Wood

Petrified Wood (Silicified Wood)

Concretion (likely iron-rich sandstone or claystone concretion) (Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing) — sedimentary

Concretion (likely iron-rich sandstone or claystone concretion)

Diagenetic carbonate/iron-oxide concretion; exact mineralogy requires testing

Chert (often called Jasper or Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Jasper or Flint)

Microcrystalline Quartz (SiO2)

Chert (Common Opal/Agatized Rock) (Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica) — sedimentary

Chert (Common Opal/Agatized Rock)

Microcrystalline Quartz (SiO2) with potential Chalcedony/Opaline silica

Chert with Quartz Veining (Silicon Dioxide (SiO2)) — sedimentary

Chert with Quartz Veining

Silicon Dioxide (SiO2)

Jasper (Jasper (Cryptocrystalline variety of Quartz, SiO2)) — sedimentary

Jasper

Jasper (Cryptocrystalline variety of Quartz, SiO2)

Chert (with Quartz vein) (Chert (Silicon Dioxide, SiO2)) — sedimentary

Chert (with Quartz vein)

Chert (Silicon Dioxide, SiO2)

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 (SiO2)) — fossil

Petrified Wood

Silicified wood (SiO2)

Chert (Jasper/Flint variant) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variant)

Microcrystalline quartz (SiO2)

Chert / River Jasper (Microcrystalline Quartz (SiO2)) — sedimentary

Chert / River Jasper

Microcrystalline Quartz (SiO2)

Ammonite Fossil (Small Pyritized or Calcitized Internal Mold) (Ammonoidea) — sedimentary

Ammonite Fossil (Small Pyritized or Calcitized Internal Mold)

Ammonoidea

Sandstone (likely Arkose or Quartz Sandstone) (Arenite (SiO2 principal component)) — sedimentary

Sandstone (likely Arkose or Quartz Sandstone)

Arenite (SiO2 principal component)

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

Chert (River Stone)

Silicon Dioxide (SiO2)

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

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

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

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

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

Petrified Wood

Fossilized Wood (SiO2 replacing organic matter)

Chert (Chert / Flint) (Silicon dioxide (SiO2) - Microcrystalline quartz) — sedimentary

Chert (Chert / Flint)

Silicon dioxide (SiO2) - Microcrystalline quartz

Sandstone Chert Concretion (Silica-cemented Concretion (primarily SiO2)) — sedimentary

Sandstone Chert Concretion

Silica-cemented Concretion (primarily SiO2)

Fossilized tooth, likely shark tooth (Fossilized selachian tooth; possibly a worn Otodus or related shark tooth) — fossil

Fossilized tooth, likely shark tooth

Fossilized selachian tooth; possibly a worn Otodus or related shark tooth

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

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

Chert (Nodular Chert)

Silicon Dioxide (SiO2)

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

Chert (Flint/Jasper variety)

Microcrystalline Quartz (SiO2)