fossil

Polished fossil shell fragment

Fossilized bivalve or gastropod shell, likely calcitic/aragonitic carbonate

AI-generated identification · may be incorrect

Tan to honey-brown, waxy to dull luster, with visible shell layering, cavities, and a darker internal band. Hardness is approximately 3–4 Mohs if calcitic, with irregular fracture and specific gravity around 2.6–2.8; the surface appears cut or polished.

Identified September 13, 2026More fossil →

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Physical properties

Formation & geological history

A marine mollusk shell was buried in carbonate-rich sediment and later mineralized or preserved, commonly during the Cenozoic or Mesozoic. Weathering and human polishing exposed the internal structure.

Uses & applications

Used as a fossil collectible, ornamental specimen, or jewelry component; it has little industrial value as an individual piece.

Geological facts

The curved growth bands and shell-wall architecture strongly indicate biological origin rather than an ordinary stone. Exact identification requires seeing the uncut shape and testing mineral composition.

Field identification & locations

Common in marine limestone deposits and fossil beds worldwide, especially coastal sedimentary regions. Look for regular growth lines, chamber or hinge features, and reaction to dilute hydrochloric acid; avoid prolonged acid exposure.