fossil

Fossilized bivalve shell

Fossil Mollusca; likely a cemented or infaunal bivalve, possibly oyster or clam

AI-generated identification · may be incorrect

Calcitic shell material, typically Mohs hardness 3–4, pearly to dull luster, white to cream coloration, and preserved growth ribs or lamellae; composition is mainly calcium carbonate (CaCO₃).

Identified August 19, 2026More fossil →

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Physical properties

Calcitic shell material, typically Mohs hardness 3–4, pearly to dull luster, white to cream coloration, and preserved growth ribs or lamellae; composition is mainly calcium carbonate (CaCO₃).

Formation & geological history

Formed when a marine bivalve shell was buried and mineralized or retained as recrystallized calcite in sedimentary rock; exact age and species require locality and microscopic examination.

Uses & applications

Primarily a fossil-collecting and educational specimen; polished or prepared shells may be decorative, but it has little industrial value.

Geological facts

The visible radial growth lines and shell curvature are biological features rather than crystal faces. Acid will usually cause weak effervescence because the shell is calcite.

Field identification & locations

Common in marine limestones and coastal sediments worldwide. Identify by shell symmetry, hinge structure, ribs, and growth lines; avoid confusing it with a modern shell or weathered limestone fragment.