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

Polished banded agate (likely picture jasper or petrified wood) (Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions) — gemstone

Polished banded agate (likely picture jasper or petrified wood)

Microcrystalline quartz, SiO₂, with iron-oxide and clay inclusions

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

Chert Nodule

Chert (Cryptocrystalline variety of Quartz, SiO2)

Moss Agate with Jasper (Chalcedony (SiO2 with inclusions)) — mineral

Moss Agate with Jasper

Chalcedony (SiO2 with inclusions)

Red Sandstone (Arenite (Iron-rich Sandstone)) — sedimentary

Red Sandstone

Arenite (Iron-rich Sandstone)

Chert Concretion (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Concretion

Microcrystalline Quartz (SiO2)

Gravel / Limestone Fragment (Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock) — sedimentary

Gravel / Limestone Fragment

Calcium Carbonate (CaCO3) / Fine-grained Sedimentary Rock

Chert (Sedimentary Rock) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Sedimentary Rock)

Silicon Dioxide (SiO2)

Sandstone with Vitrinite/Coal inclusions (Arenite with Carbonaceous inclusions) — sedimentary

Sandstone with Vitrinite/Coal inclusions

Arenite with Carbonaceous inclusions

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

Chert (Jasper/Agate mix)

Microcrystalline Quartz (SiO2)

Tufa Rock and Tumbled Gemstones (Calcareous Tufa (Calcium Carbonate, CaCO3)) — sedimentary

Tufa Rock and Tumbled Gemstones

Calcareous Tufa (Calcium Carbonate, CaCO3)

Petrified Wood (Silicified wood / Permineralized wood (SiO2)) — fossil

Petrified Wood

Silicified wood / Permineralized wood (SiO2)

Chert (Commonly called Jasper or Flint) (Chert (SiO2)) — sedimentary

Chert (Commonly called Jasper or Flint)

Chert (SiO2)

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

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

Chert (River Pebble)

Cryptocrystalline Quartz (SiO2)

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

Fossiliferous Limestone

Biogenic Limestone (Calcium Carbonate, CaCO3)

Limestone (Calcareous sedimentary rock (CaCO3)) — sedimentary

Limestone

Calcareous sedimentary rock (CaCO3)

Fossil Shell (Brachiopod or Mollusk) (Phylum Brachiopoda or Class Bivalvia (e.g., Mucrospirifer or similar genus)) — fossil

Fossil Shell (Brachiopod or Mollusk)

Phylum Brachiopoda or Class Bivalvia (e.g., Mucrospirifer or similar genus)

Calligraphy Stone (Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)) — sedimentary

Calligraphy Stone

Mariam Jasper (Fossiliferous Limestone with Hematite and Iron)

Petrified Coral (Agatized Coral) (Fossilized Anthozoa (Silicon Dioxide replacement - SiO2)) — fossil

Petrified Coral (Agatized Coral)

Fossilized Anthozoa (Silicon Dioxide replacement - SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Chert Pebble

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert Pebble (Chert (composed primarily of Microcrystalline Quartz, SiO2)) — sedimentary

Chert Pebble

Chert (composed primarily of Microcrystalline Quartz, SiO2)

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

Limestone (Weathered)

Calcium Carbonate (CaCO3)

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

Chert (Flint)

Chert (Cryptocrystalline Silicon Dioxide, SiO2)

Granite, possibly granodiorite (Coarse-grained felsic plutonic rock; chiefly quartz (SiO₂), potassium feldspar and plagioclase feldspar, with biotite and/or hornblende) — igneous

Granite, possibly granodiorite

Coarse-grained felsic plutonic rock; chiefly quartz (SiO₂), potassium feldspar and plagioclase feldspar, with biotite and/or hornblende

Chert (Smooth River Pebble) (Microcrystalline or cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Smooth River Pebble)

Microcrystalline or cryptocrystalline Quartz (SiO2)

Chert (Flint) (Chert (SiO2)) — sedimentary

Chert (Flint)

Chert (SiO2)

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

Chert (Jasper/Agate variety)

Silicon Dioxide (SiO2)

Shale (possibly Carbonaceous or Oil Shale) (Argillaceous Sedimentary Rock) — sedimentary

Shale (possibly Carbonaceous or Oil Shale)

Argillaceous Sedimentary Rock

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

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Amber (Resinite / Fossilized Tree Resin) — mineral

Amber

Resinite / Fossilized Tree Resin

Moss Agate (Chalcedony (Silicon Dioxide / SiO2)) — mineral

Moss Agate

Chalcedony (Silicon Dioxide / SiO2)

Starfish Fossil (Asteroidea fossil) — fossil

Starfish Fossil

Asteroidea fossil

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

Petrified Wood

Silicified Wood (primarily SiO2)

Chert Pebble (Microcrystalline quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline quartz (SiO2)

Fossiliferous Limestone (Carbonate Sedimentary Rock (primarily CaCO3)) — sedimentary

Fossiliferous Limestone

Carbonate Sedimentary Rock (primarily CaCO3)

Fossil Coral (Rugose Coral Fragment) (Rugosa (extinct order of solitary and colonial corals)) — sedimentary

Fossil Coral (Rugose Coral Fragment)

Rugosa (extinct order of solitary and colonial corals)

Lapis Lazuli (Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)) — metamorphic

Lapis Lazuli

Lazurite-rich metamorphic rock ((Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

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

Anthracite Coal

Anthracite (Carbon-based organic sedimentary/metamorphic rock)

Graphite Schist (C (Carbonaceous Schist)) — metamorphic

Graphite Schist

C (Carbonaceous Schist)

Sandstone (Pebble/Cobble) (Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)) — Sedimentary

Sandstone (Pebble/Cobble)

Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)

Chert (varietal Chalcedony or Flint) (Silicon dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (varietal Chalcedony or Flint)

Silicon dioxide (SiO2) - Microcrystalline Quartz