fossil
Fossilized Oyster Shell
Ostrea / Exogyra (Phylum Mollusca)
Hardness of 3-4 (calcite/aragonite), whitish to brownish-grey color, dull to pearly luster, foliated or chalky micro-structure, conchoidal to uneven fracture.
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Physical properties
Hardness of 3-4 (calcite/aragonite), whitish to brownish-grey color, dull to pearly luster, foliated or chalky micro-structure, conchoidal to uneven fracture.
Formation & geological history
Formed in marine environments through the accumulation of calcium carbonate shell material in shallow coastal waters, often dating from the Cretaceous to Cenozoic periods.
Uses & applications
Used primarily in fossil collecting, educational displays, and sometimes lapidary or decorative arts when well-preserved or agatized.
Geological facts
Fossilized oyster shells are among the most common invertebrate fossils found worldwide, often indicating ancient sea level changes and shallow marine depositional environments.
Field identification & locations
Easily identified by their irregular, cupped shell shape and foliated layered structure. Commonly found in limestone and marl formations in regions with ancient marine history.
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