fossil

Fossil coral (likely honeycomb/tabulate coral)

Fossilized colonial coral; possibly Favositidae (Favosites)

AI-generated identification · may be incorrect

A silicified or calcite-replaced fossil with tightly packed polygonal corallites, pale gray-beige color, dull to subtly waxy luster, and no obvious cleavage. Hardness is typically about 3–7 Mohs depending on whether calcite or silica replaced the original skeleton; specific gravity is approximately 2.6–2.7.

Identified September 6, 2026More fossil →

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Physical properties

Formation & geological history

Built by a colonial marine coral during the Paleozoic Era, commonly Ordovician through Devonian (about 485–359 million years ago), then buried and mineralized. The rounded shape and weathered surface indicate erosion from carbonate bedrock or glacial/alluvial gravel.

Uses & applications

Primarily a collectible and educational fossil; polished pieces are used decoratively, while calcitic coral can be cut into cabochons or ornamental stone. It has little industrial value as an individual specimen.

Geological facts

The honeycomb pattern represents individual corallite tubes, not pores in ordinary limestone. Exact identification requires a close-up of the cell walls and geological locality.

Field identification & locations

Look for consistent polygonal tubes across a broken or weathered surface; acid may fizz if calcitic, while silica-replaced specimens do not. Common in Paleozoic limestone regions such as the Great Lakes, parts of Canada, Europe, and Australia.