fossil

Fossil coral

Fossilized colonial coral, likely honeycomb or branching coral (order Tabulata or Scleractinia); exact genus is indeterminate from the image

AI-generated identification · may be incorrect

Cream-colored, porous calcareous skeleton with repeated corallite pits; low luster, brittle, and mainly calcite or aragonite recrystallized to calcite. Mohs hardness is about 3–4; no obvious cleavage; specific gravity typically 2.6–2.8.

Identified September 15, 2026More fossil →

Explore Fossil coral in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Fossil coral
Scientific name: Fossilized colonial coral, likely honeycomb or branching coral (order Tabulata or Scleractinia); exact genus is indeterminate from the image
Category: fossil
Identified: September 15, 2026
Method: Standard

AI Estimated Value

About $10–$75 for a common hand specimen; $100–$300+ for large, well-preserved, scientifically identified examples.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

A colonial marine coral skeleton lithified and commonly permineralized or recrystallized during burial. Fossil corals range from Paleozoic to Cenozoic age; the exact age requires locality and microscopic identification.

Uses & applications

Used as a collectible fossil, educational specimen, and occasionally as decorative stone or jewelry after polishing; porous pieces are generally unsuitable for structural construction.

Geological facts

The holes are corallites—individual chambers occupied by coral polyps—not ordinary weathering cavities. Fossil coral is not the same as modern reef coral and may preserve distinctive honeycomb or septate patterns.

Field identification & locations

Identify it by regular repeated cups or tubes, carbonate composition, and marine-fossil texture; common in limestone deposits worldwide, especially Florida, the Caribbean, Europe, and parts of Asia. Vinegar may weakly fizz on a fresh surface.