sedimentary
Staghorn Coral Specimen
Acropora cervicornis (Calcium Carbonate, CaCO3)
Hardness: 3-4 (Mohs); Color: White to creamy tan (bleached/dried); Luster: Dull, matte, or earthy; Structure: Branching aragonite exoskeleton with small pits (corallites); Specific Gravity: ~2.7
- Hardness
- 3-4 (Mohs)
- Color
- White to creamy tan (bleached/dried)
- Luster
- Dull, matte, or earthy
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Physical properties
Hardness: 3-4 (Mohs); Color: White to creamy tan (bleached/dried); Luster: Dull, matte, or earthy; Structure: Branching aragonite exoskeleton with small pits (corallites); Specific Gravity: ~2.7
Formation & geological history
Biogenic formation by marine polyps in tropical reef environments. As a carbonate structure, it is considered a component of sedimentary limestone processes. Age ranges from modern (Holocene) to fossilized specimens from the Pleistocene.
Uses & applications
Used in aquarium decoration, jewelry (when polished), architectural accents, and historically as a source for lime/cement. Highly valued as a bioindicator for reef health.
Geological facts
Coral is a 'biomineral' secreted by living organisms. Staghorn coral is one of the fastest-growing corals, but is currently listed as a critically endangered species in many regions, making the collection of living specimens illegal under CITES.
Field identification & locations
Identified by its distinctive antler-like branching pattern and tiny pore-like openings on the surface. Found in tropical waters of the Caribbean and Atlantic. Collectors should ensure specimens were ethically and legally sourced.
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