Calcite-rich limestone (possibly fossiliferous limestone)
Calcite, CaCO₃, in a limestone matrix
sedimentary
Category
Mineral (Biogenic)
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
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Chert (Flint)
Microcrystalline or cryptocrystalline quartz (SiO2)
sedimentary
Chert (and Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Fossils
sedimentary
Black Pearl (Tahitian Type)
Aragonite / Conchiolin composite (CaCO3)
mineraloid
Pearl (Biogenic Gemstone)
Calcium Carbonate (Aragonite and Calcite) with Conchiolin
gemstone
Limestone with possible fossil inclusions
Sedimentary Calcium Carbonate (CaCO3)
sedimentary
Shell Cameo
Cypraecassis rufa (Bullmouth Queen Helmet Shell)
mineraloid / biogenic specimen
Queen Conch Shell (Biogenic Calcium Carbonate)
Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)
mineral
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Fragments
sedimentary
Fossiliferous Limestone
Biogenic Limestone (CaCO3 with fossil fragments)
sedimentary
Fossiliferous Jasper / Miriam Stone / Elephant Skin Jasper
Biogenic Chalcedony / Silicified Fossiliferous Limestone
fossil
Mother of Pearl (Nacre) / Shell Fragment
Biogenic Calcium Carbonate (Aragonite and Conchiolin)
fossil
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcite, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Sedimentary Rock (primarily CaCO3)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
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
Stromatolite (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
sedimentary
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
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone (Coquina)
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
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone (with Rugose Coral)
Limestone with Tetracoralla (Rugosa) fossil
fossil
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with marine fossils
fossil
Likely weathered gray flint/chert pebble
Microcrystalline quartz (SiO₂), commonly with chalcedony and minor impurities
sedimentary
Red Coral (Precious Coral)
Corallium rubrum (Calcium Carbonate, CaCO3)
gemstone
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Chert (Jasper / Flint)
Microcrystalline Quartz (SiO2) with Iron Oxides
sedimentary
Staghorn Coral Specimen
Acropora cervicornis (Calcium Carbonate, CaCO3)
sedimentary
Chert (Nodular Chert)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Chert / Flint
Microcrystalline Quartz (SiO2)
sedimentary