sedimentary

Coquina (Hag Stone variant)

Biocalcarenite (Coquina)

AI-generated identification · may be incorrect

Hardness: 2-3 (Mohs scale); Color: Tan, cream, off-white; Luster: Dull to earthy; Composition: Skeletal fragments of mollusks and invertebrates; Structure: Porous, clastic texture with natural perforations.

Hardness: 2-3 (Mohs scale)
Color: Tan, cream, off-white
Luster: Dull to earthy

Identified April 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in high-energy marine environments where shell fragments accumulate and are cemented together by calcium carbonate. This specific specimen has undergone mechanical erosion (wave action) to create natural holes.

Uses & applications

Used in landscaping, historical road construction (Florida/coastal regions), and as cultural amulets or 'fairy stones' in folklore.

Geological facts

Rocks with natural holes, like this one, are often called 'Hag Stones' in folklore and were historically believed to ward off evil or provide protection to sailors.

Field identification & locations

Look for rounded, weathered edges and natural circular perforations called 'vugs'. Found commonly along shorelines with high shell concentration or ancient seafloors.