fossil

Tumbled fossil coral

Fossilized colonial coral, commonly Favositidae or related tabulate coral

AI-generated identification · may be incorrect

Cream-white, smoothly polished, with dense dark pinhole-like corallite patterns; typically calcite, Mohs hardness 3–4, vitreous to dull luster, and no obvious cleavage. The regular honeycomb texture distinguishes coral from ordinary limestone.

Identified September 10, 2026More fossil →

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Physical properties

Formation & geological history

Ancient reef-building coral was buried and mineralized, usually replaced or infilled by calcite or silica during diagenesis. Many specimens are Paleozoic, roughly 250–450 million years old, though age depends on locality.

Uses & applications

Primarily a collectible, lapidary, and jewelry material; polished pieces are used for cabochons, carvings, and decorative stones. It has little industrial value in this small form.

Geological facts

Fossil coral preserves the growth structures of colonial animals and can resemble snowflakes, honeycomb, or tiny rosettes when cut and polished.

Field identification & locations

Identify it by consistent repeated corallite pits throughout the stone, unlike random pores in pumice or shell fragments. Common sources include the Great Lakes region, Florida, Indonesia, Morocco, and Australia.