Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
sedimentary
Category
Organic Gemstone (Biogenic)
Browse organic gemstone (biogenic) specimens identified by the Rock Identifier community.
Learn about Organic Gemstone (Biogenic) in the encyclopedia
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Coquina
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Pearl (Biogenic)
Nacre / Calcium Carbonate (CaCO3)
mineral
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate Matrix with Biogenic Inclusions (CaCO3)
fossil
Pearl
Calcium Carbonate (Aragonite and Calcite), CaCO3
mineral
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Black Pearl (Tahitian Style)
Calcium Carbonate (Aragonite) - CaCO3 with Conchiolin
mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineraloid
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
sedimentary
Limestone (Fossiliferous)
Sedimentary Carbonate Rock (CaCO3)
sedimentary
Fossiliferous Jasper / Miriam Stone / Elephant Skin Jasper
Biogenic Chalcedony / Silicified Fossiliferous Limestone
fossil
Banded Chert
Microcrystalline Quartz (SiO2)
sedimentary
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
sedimentary
Tumbled brown chert (likely flint)
Microcrystalline quartz/chalcedony, SiO₂
sedimentary
Fossiliferous Limestone containing a Brachiopod or Mollusk Impression
Biogenic Sedimentary Rock / Fossiliferous Limestone
sedimentary
Fossiliferous Limestone
CaCO3 (principally Calcite or Aragonite)
sedimentary
Chert (Flint / Jasper / Hornstone)
Microcrystalline Quartz (SiO2)
sedimentary
Mixed Gemstone Collection
SiO2 (Quartz varieties) and Biogenic CaCO3 (Nacre)
mineral
Fossiliferous Limestone / Fossil Fragment
Calcium Carbonate (CaCO3) with indeterminate biogenic remains
fossil
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
mineral
Pearl
Aragonite (CaCO3) with Conchiolin
mineral
Possible fossilized shell or coral fragment
Indeterminate biogenic carbonate, likely calcite (CaCO₃)
fossil
Green Chert (Jasper / Flint)
Silicon Dioxide (SiO2)
sedimentary
Fossiliferous Limestone (Coquina / Shell Limestone)
Bioclastic Limestone (CaCO3)
sedimentary
Pearl necklace with small blue-green gemstone accents
Pearls: nacre, chiefly aragonite (CaCO₃) and conchiolin; accents appear to be turquoise or similar opaque blue-green stone
gemstone
Amber
Succinite (Organic Gemstone)
mineral
Flint (chert), likely a worked or fractured nodule
Microcrystalline quartz/chalcedony (SiO₂)
sedimentary
Flint (chert), likely brown flint
Microcrystalline quartz/chalcedony (SiO₂)
sedimentary
Pearl
Calcium Carbonate (CaCO3)
mineral
Pearl stud earrings
Pearl, primarily aragonite (CaCO₃) and conchiolin
gemstone
Pearl-embellished decorative cross
Pearl (biogenic calcium carbonate, predominantly aragonite) with rhinestone-mounted glass or synthetic gemstones
gemstone
Red Coral
Corallium rubrum
gemstone
Amber
Succinrite (Organic Gemstone)
mineraloid
Amber
Organic gemstone (Succinite)
mineral
Amber
Succinates (Organic Gemstone)
mineral
Black flint (chert)
Microcrystalline quartz/chalcedony (SiO₂)
sedimentary
Pearl (as a Biogenic Mineral)
Calcium Carbonate (mostly Aragonite) with Conchiolin; CaCO3
mineral
Fossiliferous Limestone (Gastropod / Crinoid Fossil Rock)
Biogenic Sedimentary Rock (CaCO3)
fossil
Pearl (in a decorative hair comb setting)
Calcium carbonate (CaCO3) primarily as Aragonite, bonded with Conchiolin
Organic Mineraloid