fossil

Fossilized coral or carbonate fossil fragment

Calcareous fossil, likely colonial coral (order Hexacorallia; uncertain from image)

AI-generated identification · may be incorrect

Pale white to tan, porous and irregular, enclosed in gray-green matrix; chiefly calcite/aragonite (CaCO₃), Mohs hardness about 3, dull to slightly waxy luster, with no obvious cleavage. The rounded, chambered/porous forms suggest fossil skeletal material rather than a crystalline mineral.

Identified August 12, 2026More fossil →

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Physical properties

Formation & geological history

Likely a marine carbonate fossil preserved by mineral replacement or cementation in limestone/mudstone; age cannot be determined from the image and may range from Paleozoic to Cenozoic.

Uses & applications

Primarily a teaching or collecting specimen; fossiliferous limestone may be used as aggregate, cement raw material, or ornamental stone, but this small specimen has no industrial use.

Geological facts

Acid testing with dilute hydrochloric acid or vinegar should produce visible fizz if carbonate is exposed, though coatings or silicification may suppress it.

Field identification & locations

Look for repeated corallite cups, honeycomb pores, or radial septa under magnification; common sources include marine limestone deposits worldwide. Avoid destructive testing and keep provenance information.