Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Category
Sedimentary (Biogenic)
Browse sedimentary (biogenic) specimens identified by the Rock Identifier community.
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Stromatolite
Biogenic Sedimentary Rock (composed predominantly of CaCO3)
sedimentary
Spondylus Oyster Calcification / Fossilized Oyster
Spondylus (Thorny Oyster) / Calcium Carbonate (CaCO3)
sedimentary
Devil's Toenail
Gryphaea (extinct genus of foam oysters, typically composed of Calcite CaCO3)
sedimentary
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Bioclastic Limestone
sedimentary
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Mother of Pearl (Nacre)
Aragonite with Conchiolin (CaCO3)
mineral
Fossiliferous Limestone
Autochthonous Biogenic Sedimentary Rock (CaCO3)
sedimentary
Stromatolite
Laminated biogenic sedimentary structure (Cyanobacteria)
sedimentary
Limestone with possible fossil inclusions
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Hag Stone
Perforated Sedimentary Rock (typically Limestone or Sandstone)
sedimentary
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
mineral
Land Snail Shell
Gastropoda (Calcium Carbonate, CaCO3)
fossil
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
mineral
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Oyster Shell (Biogenic Calcium Carbonate)
Crassostrea virginica (or related species) - Calcium Carbonate (CaCO3)
sedimentary
Chert
Chert (Microcrystalline Quartz, SiO2)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Chalk
Calcium Carbonate (CaCO3) - Biogenic Limestone
sedimentary
Fossiliferous Chert (with Fossil Shells)
Silicon Dioxide (SiO2) with biogenic inclusions
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Stromatolite (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Fossiliferous Limestone (Murchisonia/Gastropod Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina or Fossilized Shell Fragment
Calcium Carbonate (CaCO3) / Biogenic Limestone
sedimentary
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary