Rock Identifier
Fossilized Bivalve Shell (Class Bivalvia) — fossil
fossil

Fossilized Bivalve Shell

Class Bivalvia

AI-generated identification · may be incorrect

Mohs hardness 3-4, colors range from grey to brown or green, pearly or dull luster, composed primarily of calcium carbonate in aragonite or calcite crystal structure.

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Physical properties

Mohs hardness 3-4, colors range from grey to brown or green, pearly or dull luster, composed primarily of calcium carbonate in aragonite or calcite crystal structure.

Formation & geological history

Formed through permineralization where original shell material is replaced by minerals over thousands to millions of years in aquatic sedimentary environments.

Uses & applications

Valued by fossil collectors, used in educational displays, and studied for paleoenvironmental reconstruction.

Geological facts

Bivalves first appeared in the Cambrian period over 500 million years ago and include clams, oysters, and mussels.

Field identification & locations

Identify by distinct hinged symmetrical shells with growth rings; commonly found in sedimentary rock layers near ancient marine or freshwater deposits.

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Bioclastic limestone, composed chiefly of calcite (CaCO₃)

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Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

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Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image

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