fossil

Fossilized Bivalve Shell

Class Bivalvia (fossilized)

Hardness: 3-4 (Mohs scale, depending on calcite/aragonite preservation); Color: Pale grey or tan; Luster: Vitreous to dull; Crystal structure: Trigonal (calcite); Cleavage: Perfect rhombohedral when purely mineralized; Specific Gravity: 2.7-2.9

Color: Pale grey or tan
Luster: Vitreous to dull

Identified August 4, 2026More fossil →

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Physical properties

Formation & geological history

Formed when marine organisms were buried in sediment, allowing minerals like calcium carbonate or silica to replace the original organic material over thousands to millions of years.

Uses & applications

Educational purposes, fossil collecting, and decorative items.

Geological facts

Fossilized shells provide crucial clues about ancient marine environments, sea level changes, and evolutionary history.

Field identification & locations

Found commonly in sedimentary rock formations such as limestone, shales, and sandstone, particularly in regions that were once covered by ancient seas.

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Fossilized Crinoid Stem in Limestone

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Fossiliferous Limestone

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