Pearl
Aragonite and Conchiolin (CaCO3 + organic protein)
mineraloid
Category
Mineral (Biogenic)
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
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Water and Silt (Sedimentary Environment)
Suspended Sediment / H2O (dihydrogen monoxide)
sedimentary
Iron-stained chert or siliceous mudstone
Microcrystalline quartz (SiO₂), likely chert with hematite/goethite staining
sedimentary
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Bioclasts
sedimentary
Coquina
Bioclastic Limestone
sedimentary
Chert
Silicon dioxide (SiO2)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone (with Crinoids/Coral)
Fossiliferous Limestone (CaCO3)
sedimentary
Limestone with Chert
Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions
sedimentary
Chert (Jasper/Limonitic Chert)
Cryptocrystalline Quartz (SiO2) with Iron Oxide (FeO(OH)) inclusions
sedimentary
Chert (Nodule)
Microcrystalline Silica (SiO2)
sedimentary
Weathered iron-rich chert or jasper
Microcrystalline quartz (SiO₂), commonly colored by iron oxides/hydroxides
sedimentary
Chert (Flint / Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Pearl (Biogenic Gemstone)
Calcium Carbonate (Aragonite and Calcite) with Conchiolin
gemstone
Weathered chert or siliceous limestone
Microcrystalline quartz (SiO₂), possibly replacing or cementing carbonate rock
sedimentary
White coral limestone (probable fossiliferous limestone)
Calcite (CaCO₃), commonly derived from aragonitic coral skeletons recrystallized to calcite
sedimentary
Freshwater Pearl
Calcium Carbonate (CaCO3) in the form of Aragonite and Calcite
gemstone
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 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 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