Rock Identifier

Category

Organic (Geological Interest)

Browse organic (geological interest) specimens identified by the Rock Identifier community.

Amber (Succinite / Fossilized Resin (C10H16O)) — fossil

Amber

Succinite / Fossilized Resin (C10H16O)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Pearl jewelry (Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)) — gemstone

Pearl jewelry

Pearl (biogenic calcium carbonate, primarily aragonite, CaCO₃)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Calcite crystal cluster (Calcite (calcium carbonate, CaCO₃)) — mineral

Calcite crystal cluster

Calcite (calcium carbonate, CaCO₃)

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

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Petrified Wood (Silicified wood (Quartz/Chalcedony/Opal)) — sedimentary

Petrified Wood

Silicified wood (Quartz/Chalcedony/Opal)

Likely pyrite-bearing rock fragment (Pyrite, FeS₂, possibly in a dark host rock) — mineral

Likely pyrite-bearing rock fragment

Pyrite, FeS₂, possibly in a dark host rock

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

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

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

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (specifically Green Chert/Jasper) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — sedimentary

Chert (specifically Green Chert/Jasper)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz

Chert (Red/Pink Jasper subtype) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Red/Pink Jasper subtype)

Silicon Dioxide (SiO2)

Chert (Iron-stained) (Chert (primarily Microcrystalline Quartz, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (primarily Microcrystalline Quartz, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Fossil Shell (Bivalve) (Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3) — sedimentary

Fossil Shell (Bivalve)

Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Honey-colored chert or flint fragment (Microcrystalline quartz (SiO₂), likely chalcedony-rich chert) — sedimentary

Honey-colored chert or flint fragment

Microcrystalline quartz (SiO₂), likely chalcedony-rich chert

Moss Agate (Chalcedony (Silicon Dioxide, SiO2) with inclusions) — mineral

Moss Agate

Chalcedony (Silicon Dioxide, SiO2) with inclusions

Green Chert (Silicon Dioxide (SiO2)) — sedimentary

Green Chert

Silicon Dioxide (SiO2)

Sand Tiger Shark Tooth (Carcharias taurus) — fossil

Sand Tiger Shark Tooth

Carcharias taurus

Fossilized shell or bone fragment (Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone) — fossil

Fossilized shell or bone fragment

Indeterminate biogenic carbonate/phosphate fossil; likely a fragment of fossil shell or small vertebrate bone

Chert (and Fossilized Brachiopod shell) (Sedimentary Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

River Stone (Chert/Siltstone) (Cryptocrystalline Quartz (SiO2) with trace impurities) — sedimentary

River Stone (Chert/Siltstone)

Cryptocrystalline Quartz (SiO2) with trace impurities

Honey calcite (likely) (Calcite, calcium carbonate (CaCO₃)) — mineral

Honey calcite (likely)

Calcite, calcium carbonate (CaCO₃)

Flint (chert), likely brown flint (Microcrystalline quartz/chalcedony (SiO₂)) — sedimentary

Flint (chert), likely brown flint

Microcrystalline quartz/chalcedony (SiO₂)

Chert Nodule (Microcrystalline Silica (SiO2)) — sedimentary

Chert Nodule

Microcrystalline Silica (SiO2)

Petrified Wood (Silicon Dioxide Fossilized Wood (SiO2)) — fossil

Petrified Wood

Silicon Dioxide Fossilized Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — mineral

Petrified Wood

Silicified Wood (SiO2)

Likely bituminous coal (Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed visually) — sedimentary

Likely bituminous coal

Coal, predominantly carbon-rich organic matter; exact rank cannot be confirmed visually

Chalcedony or Chert/Jasper with secondary mineral staining (SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.) — Mineral, potentially a rock with chalcedony/jasper.

Chalcedony or Chert/Jasper with secondary mineral staining

SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.

Mineral, potentially a rock with chalcedony/jasper.

Chalcedony / Agate with Botryoidal Quartz (Silicon Dioxide (SiO2)) — sedimentary

Chalcedony / Agate with Botryoidal Quartz

Silicon Dioxide (SiO2)

Petrified Wood (Silicified Wood (SiO2 - Quartz/Chalcedony replacement)) — Mineral / Fossil

Petrified Wood

Silicified Wood (SiO2 - Quartz/Chalcedony replacement)

Mineral / Fossil

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood (Silicified Wood (SiO2)) — sedimentary

Petrified Wood

Silicified Wood (SiO2)

Chert (or Flint) (Chert (Sedimentary Cryptocrystalline Sio2)) — sedimentary

Chert (or Flint)

Chert (Sedimentary Cryptocrystalline Sio2)

Petrified Wood (Silicified wood (Quartz variant, SiO2)) — sedimentary

Petrified Wood

Silicified wood (Quartz variant, SiO2)

Pearl oyster shell with cultured pearls (Mollusk shell (likely Pinctada spp.) containing aragonite pearls, CaCO₃) — gemstone

Pearl oyster shell with cultured pearls

Mollusk shell (likely Pinctada spp.) containing aragonite pearls, CaCO₃

Flint or chert, possibly a knapped stone tool (Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities) — sedimentary

Flint or chert, possibly a knapped stone tool

Microcrystalline quartz (SiO₂), commonly chalcedony with possible carbonaceous impurities

Weathered fossiliferous limestone (Calcitic limestone, predominantly calcite (CaCO₃), possibly bioclastic) — sedimentary

Weathered fossiliferous limestone

Calcitic limestone, predominantly calcite (CaCO₃), possibly bioclastic