fossil

Coral Fossil

Anthozoa (Scleractinia)

Hardness: 3-4 (Mohs), Color: Cream, white, or light tan, Luster: Dull to earthy, Structure: Calcified porous skeleton with visible corallite patterns, Specific Gravity: 2.5-2.7

Identified July 5, 2026More fossil →

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Physical properties

Hardness: 3-4 (Mohs), Color: Cream, white, or light tan, Luster: Dull to earthy, Structure: Calcified porous skeleton with visible corallite patterns, Specific Gravity: 2.5-2.7

Formation & geological history

Formed through the fossilization of marine coral polyps, typically in shallow tropical marine environments. Can range from Recent to many millions of years old depending on the strata.

Uses & applications

Used in decorative aquarium landscaping, garden features, specimen collecting, and occasionally as a source of calcium carbonate in industrial applications.

Geological facts

Fossilized coral is a primary component of limestone. Many Florida and Caribbean islands are built upon ancient coral reefs that were exposed as sea levels changed.

Field identification & locations

Identify by looking for a porous, honeycomb, or branching structure that is heavier than plastic but reacts (fizzes) with weak acids like vinegar. Commonly found on beaches or in limestone quarries.