fossil

Fossilized oyster shell

Bivalvia; likely an oyster (Ostreidae), partly mineralized with calcite

AI-generated identification · may be incorrect

Irregular layered shell form, pale gray-white exterior, yellow-brown weathering, and visible calcitic shell material. Calcite hardness is about 3 Mohs, with pearly to dull luster; shell fossils commonly retain curved growth layers and cavities.

Identified August 11, 2026More fossil →

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Physical properties

Formation & geological history

A marine bivalve shell buried in sediment and later preserved through permineralization or replacement, commonly during the Cenozoic or Mesozoic. Exact age requires locality and microscopic or chemical analysis.

Uses & applications

Primarily a collecting, educational, and decorative specimen; polished or prepared fossil shells may be used in display pieces. It has little industrial value compared with nonfossil limestone or shell aggregate.

Geological facts

Oyster shells are made mainly of calcium carbonate, typically calcite, and their irregular shape reflects attachment to hard substrates. Yellow coloration commonly results from iron-bearing minerals or weathering.

Field identification & locations

Identify by the thick, uneven valve, layered growth bands, and shell curvature; dilute acid may weakly fizz, though testing can damage it. Common in shallow-marine limestone and coastal fossil beds worldwide.