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

Sandstone (Arenite (primarily SiO2)) — sedimentary

Sandstone

Arenite (primarily SiO2)

Fossil Shell (Bivalve) (Class Bivalvia (fossilized)) — fossil

Fossil Shell (Bivalve)

Class Bivalvia (fossilized)

Piddock bored rock (Boring Stone) (Ichnofossil-bearing Limestone or Mudstone (trace fossils by Pholadidae)) — sedimentary

Piddock bored rock (Boring Stone)

Ichnofossil-bearing Limestone or Mudstone (trace fossils by Pholadidae)

Brachiopod Fossil (Brachiopoda (Phylum); often Atrypa or Mucrospirifer genus depending on locality) — fossil

Brachiopod Fossil

Brachiopoda (Phylum); often Atrypa or Mucrospirifer genus depending on locality

Fossilized Brachiopod (Phylum Brachiopoda (replaced by Calcite/CaCO3)) — sedimentary

Fossilized Brachiopod

Phylum Brachiopoda (replaced by Calcite/CaCO3)

Sandstone Pebbles (Arenite) — sedimentary

Sandstone Pebbles

Arenite

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

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Yellow Jasper (Silicon Dioxide (SiO2) with iron inclusions) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Fossiliferous Limestone (Limestone with fossil bioclasts (Calcium Carbonate, CaCO3)) — sedimentary

Fossiliferous Limestone

Limestone with fossil bioclasts (Calcium Carbonate, CaCO3)

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

Petrified Wood

Silicified Wood (primarily SiO₂ - Silicon Dioxide)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Arenite (SiO2 with various cementing minerals)) — sedimentary

Sandstone

Arenite (SiO2 with various cementing minerals)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Limestone (Sedimentary Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Chert with Calcite Veining (Microcrystalline Quartz (SiO2) with Calcium Carbonate (CaCO3) veins) — sedimentary

Chert with Calcite Veining

Microcrystalline Quartz (SiO2) with Calcium Carbonate (CaCO3) veins

Weathered volcanic rock, likely andesite or basalt (Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals) — igneous

Weathered volcanic rock, likely andesite or basalt

Fine-grained mafic to intermediate volcanic rock; probable andesite–basalt, compositionally dominated by plagioclase with pyroxene and possibly alteration minerals

Crushed Limestone (Calcium Carbonate (CaCO3)) — Sedimentary

Crushed Limestone

Calcium Carbonate (CaCO3)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Fossil Shell in Sedimentary Matrix (Bivalvia (fossil) in Calcium Carbonate Matrix) — sedimentary

Fossil Shell in Sedimentary Matrix

Bivalvia (fossil) in Calcium Carbonate Matrix

Fossiliferous Limestone (with Coralline Inclusions) (Calcium Carbonate (CaCO3)) — sedimentary

Fossiliferous Limestone (with Coralline Inclusions)

Calcium Carbonate (CaCO3)

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Fossilized Echinoid (Sea Urchin) or Brachiopod (Echinoidea / Invertebrate Fossil) — fossil

Fossilized Echinoid (Sea Urchin) or Brachiopod

Echinoidea / Invertebrate Fossil

Fossilized Brachiopod or Gastropod in Chert/Limestone (Phylum Brachiopoda / Mollusca) — fossil

Fossilized Brachiopod or Gastropod in Chert/Limestone

Phylum Brachiopoda / Mollusca

Fossilized Brachiopod in Limestone (Phylum Brachiopoda embedded in sedimentary limestone) — fossil

Fossilized Brachiopod in Limestone

Phylum Brachiopoda embedded in sedimentary limestone

Banded Agate (specifically Moss Agate or Plume Agate variety) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Banded Agate (specifically Moss Agate or Plume Agate variety)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Manganese Oxide Crust on Limestone (Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3) — sedimentary

Manganese Oxide Crust on Limestone

Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3

Ammonite Fossil (Ammonoidea) — fossil

Ammonite Fossil

Ammonoidea

Fossilized Shark Tooth (Chondrichthyes (Class)) — fossil

Fossilized Shark Tooth

Chondrichthyes (Class)

Fossil Shark Tooth (Odontaspididae (Sand Tiger Shark family)) — fossil

Fossil Shark Tooth

Odontaspididae (Sand Tiger Shark family)

Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Polished dendritic jasper or agate slab (Microcrystalline quartz (SiO₂), likely jasper with chalcedony and iron/manganese dendrites) — mineral

Polished dendritic jasper or agate slab

Microcrystalline quartz (SiO₂), likely jasper with chalcedony and iron/manganese dendrites

Arid Sandy Loam (Arenosols / Regosols) — sedimentary

Arid Sandy Loam

Arenosols / Regosols

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Tumbled amber-like chalcedony or resinous fossil material (Likely chalcedony (microcrystalline SiO₂), though the appearance could also indicate copal/amber) — gemstone

Tumbled amber-like chalcedony or resinous fossil material

Likely chalcedony (microcrystalline SiO₂), though the appearance could also indicate copal/amber

Fossil Rugose Coral (Horn Coral) (Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)) — sedimentary

Fossil Rugose Coral (Horn Coral)

Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)

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

Limestone (Weathered)

Calcium Carbonate (CaCO3)

Shale (Shale (composition varies: primarily clay minerals and quartz)) — sedimentary

Shale

Shale (composition varies: primarily clay minerals and quartz)

Hardpan Nodule / Ferruginous Sandstone (Ferruginous Sandstone (Fe-cemented sediment)) — sedimentary

Hardpan Nodule / Ferruginous Sandstone

Ferruginous Sandstone (Fe-cemented sediment)

Sandstone (Clastic sedimentary rock (primarily Quartz)) — sedimentary

Sandstone

Clastic sedimentary rock (primarily Quartz)

Fossilized Coral (Hexagonaria (Rugose and Tabulate coral fossils)) — fossil

Fossilized Coral

Hexagonaria (Rugose and Tabulate coral fossils)

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)