Rock Identifier

Category

Organic (Biological Organism)

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

Learn about Organic (Biological Organism) in the encyclopedia

Sapropel

Bituminous Shale

Bituminous Shale

Black Shale

Petrified Wood

Amber

Jet

Oil Shale

Peat

Pearl

Lizard Skin Jasper

Coral Rock

Opalized Wood

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

Petrified Wood

Silicified Wood (primarily Quartz/Chalcedony, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (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)

Brown translucent mineral fragment, possibly iron-stained quartz or amber (Uncertain; likely quartz (SiO₂) with iron-oxide staining, though amber (fossilized resin) is possible) — mineral

Brown translucent mineral fragment, possibly iron-stained quartz or amber

Uncertain; likely quartz (SiO₂) with iron-oxide staining, though amber (fossilized resin) is possible

Chert Concretion (Microcrystalline Quartz (SiO2) in Carbonate Matrix) — sedimentary

Chert Concretion

Microcrystalline Quartz (SiO2) in Carbonate Matrix

Chalk (Calcium Carbonate (CaCO3)) — sedimentary

Chalk

Calcium Carbonate (CaCO3)

Fossiliferous limestone (Bioclastic limestone, predominantly calcite (CaCO₃)) — sedimentary

Fossiliferous limestone

Bioclastic limestone, predominantly calcite (CaCO₃)

Amber (Amber (Fossilized Tree Resin)) — mineral

Amber

Amber (Fossilized Tree Resin)

Amber (Fossilized Tree Resin) — gemstone

Amber

Fossilized Tree Resin

Moss Agate (SiO2) — mineral

Moss Agate

SiO2

Aragonite crystal cluster (Aragonite, orthorhombic calcium carbonate (CaCO₃)) — mineral

Aragonite crystal cluster

Aragonite, orthorhombic calcium carbonate (CaCO₃)

Concrete or asphalt-like aggregate surface with a dark fragment (Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock) — sedimentary

Concrete or asphalt-like aggregate surface with a dark fragment

Uncertain; likely artificial concrete containing mixed lithic aggregate, not a natural rock

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Sandstone (Weathered Coastal Boulder) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (Weathered Coastal Boulder)

Arenite (composed primarily of SiO2)

Petrified Wood (Silicified Wood (primarily SiO₂ - Silicon Dioxide)) — metamorphic

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

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

Petrified Wood

Silicified wood (primarily SiO2)

Petrified Wood (Silicified wood (primarily Silicon Dioxide, SiO2)) — sedimentary

Petrified Wood

Silicified wood (primarily Silicon Dioxide, SiO2)

Fossilized Shark Tooth (Fragment) (Elasmobranchii gen. indet.) — fossil

Fossilized Shark Tooth (Fragment)

Elasmobranchii gen. indet.

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Coal (Bituminous Coal / Anthracite) — sedimentary

Coal

Bituminous Coal / Anthracite

Petrified Wood (Agatized/Silicified Wood) (Silicified Paleoxylon (primarily SiO2)) — sedimentary

Petrified Wood (Agatized/Silicified Wood)

Silicified Paleoxylon (primarily SiO2)

Shale (Fissile mudrock (composed primarily of clay minerals and quartz)) — sedimentary

Shale

Fissile mudrock (composed primarily of clay minerals and quartz)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Amber (Succinite (Fossilized Tree Resin), C10H16O) — Organic Mineraloid

Amber

Succinite (Fossilized Tree Resin), C10H16O

Organic Mineraloid

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

Petrified Wood (Silicified Wood (SiO2)) — fossil

Petrified Wood

Silicified Wood (SiO2)

Slate (Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)) — metamorphic

Slate

Slate (foliated metamorphic rock, primarily composed of quartz, illite, chlorite, and micas)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Amber (Succinite (C10H16O)) — gemstone

Amber

Succinite (C10H16O)

Polished moss agate (Moss agate, a variety of chalcedony (microcrystalline quartz, SiO₂)) — gemstone

Polished moss agate

Moss agate, a variety of chalcedony (microcrystalline quartz, SiO₂)

Manganese Dendrite on Siltstone (Manganese Oxide (pyrolusite or psilomelane) Dendrites) — mineral/sedimentary

Manganese Dendrite on Siltstone

Manganese Oxide (pyrolusite or psilomelane) Dendrites

mineral/sedimentary

Amber (Succinate (Fossilized Tree Resin)) — fossil

Amber

Succinate (Fossilized Tree Resin)

Fossiliferous Chert (Brachiopod/Bryozoan Fossil) (Microcrystalline quartz (SiO2) with fossil inclusions) — sedimentary

Fossiliferous Chert (Brachiopod/Bryozoan Fossil)

Microcrystalline quartz (SiO2) with fossil inclusions

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

Chert Concretion / Nodule

Microcrystalline Quartz (SiO2)

Tumbled coral fragment (likely white calcitic coral) (Calcium carbonate, primarily aragonite or calcite (CaCO₃); exact coral genus cannot be determined from the image) — fossil

Tumbled coral fragment (likely white calcitic coral)

Calcium carbonate, primarily aragonite or calcite (CaCO₃); exact coral genus cannot be determined from the image

Calcite-rich limestone (Limestone, predominantly calcium carbonate (CaCO₃), usually calcite) — sedimentary

Calcite-rich limestone

Limestone, predominantly calcium carbonate (CaCO₃), usually calcite

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

Chert (Flint / Jasper / Hornstone)

Microcrystalline Quartz (SiO2)

Fossilized Bark (Lepidodendron / Sigillaria fossil impression) — fossil

Fossilized Bark

Lepidodendron / Sigillaria fossil impression

Yellow-orange amber (Fossilized tree resin; amber is an organic mineraloid, not a true mineral) — fossil

Yellow-orange amber

Fossilized tree resin; amber is an organic mineraloid, not a true mineral