Fossiliferous Limestone (Coquina / Shell Bed)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Category
Biogenic Material
Browse biogenic material specimens identified by the Rock Identifier community.
Learn about Biogenic Material in the encyclopedia
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Scallop Shell Fossil
Pecten sp.
fossil
Hag Stone (Holey Rock / Fossiliferous Limestone)
Limestone (CaCO3) with natural erosion / fossil cavities
sedimentary
Mother of Pearl (Nacre)
Nacre (Aragonite/Conchiolin), CaCO3 + Organic Polymers
mineral
Banded Chert / Agate
Silicon Dioxide (SiO2)
sedimentary
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Calcite in Matrix
Calcium Carbonate (CaCO3)
mineral
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Atlantic Calico Scallop (Biogenic Aragonite/Calcite)
Argopecten gibbus (Chemical: CaCO3)
mineral
Cat's Eye Shell (Shiva Shell)
Operculum of the Turbo petholatus (Tapestry Turban Snail), predominantly Calcium Carbonate (Aragonite)
mineraloid / biogenic specimen
Chert Pebble with Quartz Veining
Microcrystalline Quartz (SiO2)
sedimentary
Mookaite Jasper
Silicified Radiolarite (SiO2)
sedimentary
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Mineral
Chert (Nodule)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
sedimentary
Fossilized cylindrical shell or bone fragment
Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone
fossil
Tumbled dark stone, possibly chert or basalt
Indeterminate; likely fine-grained basalt (plagioclase–pyroxene) or microcrystalline chert (quartz, SiO₂)
igneous
Fossiliferous Limestone (or Bryozoan/Coral Fossil Pebble)
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate with Fossils)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone containing marine invertebrate fossils
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Pearl
Biogenic Calcium Carbonate (Aragonite and Conchiolin), CaCO3
mineral
Stromatolite
Biogenic Sedimentary Rock (Lithified microbial mat)
sedimentary
Chalk (Calcitic)
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
sedimentary
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Stromatolite
Laminated biogenic sedimentary structure (formed by Cyanobacteria)
sedimentary
Stromatolite
Biogenic Sedimentary Rock (Precambrian Stromatolite fossil)
sedimentary
Fossiliferous Limestone (Coquina / Shell Limestone)
Bioclastic Limestone (CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock / CaCO3 with fossil fragments
sedimentary
Beach Pebbles and Quartz Aggregates
Quartz pebbles and biogenic fragments (SiO2, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) matrix with biogenic fragments
fossil
Bay Scallop Shell
Argopecten irradians (Biogenic Calcium Carbonate / CaCO3)
sedimentary
Polished brown flint/chert (likely)
Microcrystalline quartz, SiO₂ (chalcedonic flint/chert)
sedimentary
Limestone (Chalk / Calcite Rock)
Calcium Carbonate (CaCO3)
sedimentary
Calcite
Calcite (Mineral; CaCO₃)
Mineral
Calcite
Calcite (Calcium Carbonate, CaCO3)
mineral
Jasper containing fossilized inclusions
Silicon Dioxide (SiO2) with trace impurities and biogenic inclusions
sedimentary
Chert (or Flint)
Chert (cryptocrystalline quartz), SiO2
Sedimentary