fossil

Fossil coral

Colonial scleractinian coral fossil, likely a tabulate or honeycomb coral; exact genus requires microscopy

AI-generated identification · may be incorrect

Gray-brown, silicified or calcified fossil with dense polygonal corallites and irregular borings/weathering holes; original calcite/aragonite skeleton is commonly replaced by silica or carbonate. Apparent hardness is about 4–7 depending on preservation, with dull to slightly waxy luster and no obvious cleavage.

Identified September 12, 2026More fossil →

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Physical properties

Formation & geological history

Former reef-building coral colony deposited in shallow marine limestone, commonly Paleozoic to Mesozoic in age; burial, compaction, and mineral replacement preserved the coral structure.

Uses & applications

Used as a teaching specimen, cabinet fossil, and decorative object; polished fossil coral is occasionally used in jewelry, though porous pieces are fragile.

Geological facts

The honeycomb-like pattern represents individual corallites, each once occupied by a coral polyp; holes may be natural bioerosion or later weathering rather than original coral structures.

Field identification & locations

Identify by repeating polygonal or radial corallite cells across a rock-like surface; common sources include limestone regions of the United States, Morocco, Madagascar, and Australia. A hand lens and dilute acid test can help distinguish carbonate from silicified material.