sedimentary

Fossilized Brain Coral

Diploria labyrinthiformis (Fossilized)

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale); Color: White, cream, or light tan; Luster: Dull to earthy; Structure: Sinuous, maze-like ridges (meandering septa); Cleavage: None; Composition: Calcium carbonate (Calcite/Aragonite) or Silica if silicified.

Hardness: 3-4 (Mohs scale)
Color: White, cream, or light tan
Luster: Dull to earthy

Identified June 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the fossilization of stony coral colonies. The original organic structure is replaced by minerals over thousands to millions of years in shallow marine environments. Often found in limestone deposits from the Pleistocene or Holocene.

Uses & applications

Collecting, decorative home accents, aquarium decor, and educational geological specimens.

Geological facts

The name 'Brain Coral' comes from the labyrinthine appearance which resembles the folds of a human brain. Individual polyps live in the grooves and build the calcium carbonate skeleton.

Field identification & locations

Identified by the distinct wandering grooves and ridges. Commonly found on beaches near coral reefs or in inland sedimentary rock formations that were once underwater. Collectors look for well-defined patterns and lack of erosion.