fossil

Fossilized shell or coral fragment

Indeterminate fossil; possibly a gastropod/bivalve fragment or colonial coral

AI-generated identification · may be incorrect

Pale gray-green, weathered, matte specimen with radiating or ribbed surface textures; likely calcite/aragonite replaced by calcite. Estimated hardness 3–4 Mohs, low-to-moderate density, and irregular fracture; exact properties require testing.

Identified August 26, 2026More fossil →

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Physical properties

Formation & geological history

A marine carbonate fossil formed when shell or coral was buried in sediment and mineralized during diagenesis, commonly over millions to hundreds of millions of years. The visible piece appears naturally worn or broken.

Uses & applications

Primarily a teaching, collecting, and decorative specimen; not generally valuable for industrial use or jewelry unless unusually well-preserved or scientifically significant.

Geological facts

The radiating ridges may represent shell ornamentation, septa, or coral structures, but the image is insufficient for confident taxonomic identification.

Field identification & locations

Common in marine limestone, coastal deposits, and sedimentary outcrops. Test with dilute hydrochloric acid or vinegar for effervescence, and inspect the underside for chambering, growth lines, or coral corallites; avoid destructive testing on valuable specimens.