Rock Identifier

Category

Mineral (Biogenic Replacement)

Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Fossilized Shell Fragment / Mother of Pearl (Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral) — fossil

Fossilized Shell Fragment / Mother of Pearl

Calcium Carbonate (CaCO3) - Aragonite/Calcite biomineral

Mother of Pearl (Nacre) (Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers) — mineral

Mother of Pearl (Nacre)

Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers

Chalcedony (Botryoidal) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Botryoidal)

Silicon Dioxide (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Chert (Smoky Variety) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Smoky Variety)

Microcrystalline Quartz (SiO2)

Oyster Shell (Aragonite/Calcite) (Calcium Carbonate (CaCO3)) — sedimentary

Oyster Shell (Aragonite/Calcite)

Calcium Carbonate (CaCO3)

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Banded Chert / Agate (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert / Agate

Silicon Dioxide (SiO2)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Fossilized Shark Tooth (Otodus) (Otodus sp. (calcium phosphate/hydroxylellite)) — sedimentary

Fossilized Shark Tooth (Otodus)

Otodus sp. (calcium phosphate/hydroxylellite)

Calamites (Calamites (Pith cast fossil)) — sedimentary

Calamites

Calamites (Pith cast fossil)

Fossil Coral (Scleractinia (Fossilized Hexacoral)) — fossil

Fossil Coral

Scleractinia (Fossilized Hexacoral)

Polished brecciated jasper (likely septarian or iron-rich jasper) (Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and possibly calcite or other rock fragments) — sedimentary

Polished brecciated jasper (likely septarian or iron-rich jasper)

Microcrystalline quartz (chalcedony), SiO₂, with iron oxides and possibly calcite or other rock fragments

Atlantic Calico Scallop (Biogenic Aragonite/Calcite) (Argopecten gibbus (Chemical: CaCO3)) — mineral

Atlantic Calico Scallop (Biogenic Aragonite/Calcite)

Argopecten gibbus (Chemical: CaCO3)

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Shell Cameo (Sardonyx Shell) (Cassis madagascariensis (Sardonyx shell)) — mineral (biogenic silica/calcium carbonate substrate)

Shell Cameo (Sardonyx Shell)

Cassis madagascariensis (Sardonyx shell)

mineral (biogenic silica/calcium carbonate substrate)

Fossilized Gastropod / Coral (Phylum Mollusca / Cnidaria (Silicified or Calcified)) — fossil

Fossilized Gastropod / Coral

Phylum Mollusca / Cnidaria (Silicified or Calcified)

Chert (varieties include Flint and Jasper) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (varieties include Flint and Jasper)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Fossilized Bone (Permineralized Vertebrate Bone) — fossil

Fossilized Bone

Permineralized Vertebrate Bone

Tiger's Eye (Quartz pseudomorph after crocidolite (SiO2)) — gemstone

Tiger's Eye

Quartz pseudomorph after crocidolite (SiO2)

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

Green Chert (Jasper / Flint)

Silicon Dioxide (SiO2)

Pearl (Biogenic Calcium Carbonate (Aragonite and Conchiolin), CaCO3) — mineral

Pearl

Biogenic Calcium Carbonate (Aragonite and Conchiolin), CaCO3

Tahitian Pearl (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Tahitian Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Black Freshwater Pearls (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Black Freshwater Pearls

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Pyrite (Iron Disulfide (FeS2)) — mineral

Pyrite

Iron Disulfide (FeS2)

Fluorite on Host Rock (Calcium Fluoride (CaF2)) — mineral

Fluorite on Host Rock

Calcium Fluoride (CaF2)

Pyrite (Iron Pyrite (FeS2)) — mineral

Pyrite

Iron Pyrite (FeS2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Ammonite Fossil (Ammonoidea subclass (calcium carbonate / silica replacement)) — fossil

Ammonite Fossil

Ammonoidea subclass (calcium carbonate / silica replacement)

Fossil Shell (Invertebrate fossil (Mollusca)) — fossil

Fossil Shell

Invertebrate fossil (Mollusca)

Fossilized Shark Tooth (Elasmobranchii (various species, possibly Carcharias or Odontaspis)) — fossil

Fossilized Shark Tooth

Elasmobranchii (various species, possibly Carcharias or Odontaspis)

Fossilized Shark Tooth (Otodus) (Otodus obliquus) — fossil

Fossilized Shark Tooth (Otodus)

Otodus obliquus

Chert (Jasper or Flint variant) (Chert (composed of microcrystalline quartz, SiO2)) — sedimentary

Chert (Jasper or Flint variant)

Chert (composed of microcrystalline quartz, SiO2)

Pearl (in a decorative hair comb setting) (Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin) — Organic Mineraloid

Pearl (in a decorative hair comb setting)

Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin

Organic Mineraloid

Magnetite / Lodestone (Magnetite (Fe3O4)) — mineral

Magnetite / Lodestone

Magnetite (Fe3O4)

Rhodonite (Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Inosilicate (Mn,Fe,Mg,Ca)SiO3

Baryte (Barite) (Barium sulfate (BaSO4)) — mineral

Baryte (Barite)

Barium sulfate (BaSO4)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Pyrite (Fool's Gold) (Iron Sulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)