Pearl
Biogenic CaCO3 (Aragonite and Calcite)
Category
Browse mineral (biogenic replacement) specimens identified by the Rock Identifier community.
Pearl
Biogenic CaCO3 (Aragonite and Calcite)
Ammolite
Biogenic gemstone (Aragonite, CaCO3)
Spiny Oyster Shell
Spondylus varians (Biogenic Calcium Carbonate)
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Abalone Shell (Mother of Pearl)
Aragonite (Biogenic Calcium Carbonate, CaCO3)
Pearl
Calcium Carbonate (Aragonite/Calcite mixed with Conchiolin), CaCO3
Mother of Pearl (Nacre)
Aragonite (layered with organic polymers), CaCO3
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pearl
Calcium Carbonate (CaCO3) in the form of Aragonite
Pearl
Organic Mineraloid (CaCO3 + Conchiolin)
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Pearl
Aragonite and Calcite (CaCO3) with Conchiolin
Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Calcite
Calcium Carbonate (CaCO3)
Spondylus Oyster Calcification / Fossilized Oyster
Spondylus (Thorny Oyster) / Calcium Carbonate (CaCO3)
Pearl
Calcium Carbonate (primarily Aragonite and Calcite), CaCO3
Black Pearl (Tahitian-style Cultured Pearl)
Calcium Carbonate (Aragonite) with Conchiolin (CaCO3)
Pyrite in Quartz
FeS2 (Iron Pyrite) with SiO2 (Quartz)
Pyrite
Iron Sulfide (FeS2)
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
Pearl
Aragonite (CaCO3) with Conchiolin
Fossiliferous Limestone
Limestone (CaCO3 - Calcium Carbonate)
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Baroque Pearl
Biogenic Calcium Carbonate (Aragonite/Conchiolin)
Atlantic Calico Scallop (Biogenic Aragonite/Calcite)
Argopecten gibbus (Chemical: CaCO3)
Chert (Jasper or Flint variant)
Chert (composed of microcrystalline quartz, SiO2)
Pearl
Aragonite (CaCO3) with Conchiolin
Pearl
Calcium Carbonate (Aragonite) - CaCO3
Mother of Pearl (Nacre)
Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)
Fossilized Dinosaur Skull (Tyrannosaurus rex)
Tyrannosaurus rex (permineralized fossil), rich in Hydroxylapatite/Silica
Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)
Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Blue Chalcedony
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Shell Cameo (Sardonyx Shell)
Cassis madagascariensis (Sardonyx shell)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pyrite (on host rock)
Iron Sulfide (FeS2)
Fossilized Fish (Lepidotes)
Lepidotes sp. (Order: Lepisosteiformes)