sedimentary (biogenic)

Sea Shell (Fighting Conch Fragment)

Calcium Carbonate (CaCO3) - Strombus alatus fragment

Hardness: 3.0-3.5 on Mohs scale; Color: Creamy white with brownish blotches; Luster: Pearly to dull; Structure: Calcified spiral; Cleavage: None (conchoidal fracture when broken); Specific Gravity: 2.7-2.9

Hardness: 3
Color: Creamy white with brownish blotches
Luster: Pearly to dull

Identified March 31, 2026More sedimentary (biogenic) →

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Physical properties

Formation & geological history

Formed through biological precipitation of minerals by marine gastropods in warm, shallow coastal waters. These specimens typically range from modern era to the Pleistocene age in fossilized forms found in sedimentary deposits.

Uses & applications

Used in the crafts industry for home decor, jewelry making (beads/pendants), and historical soil enrichment (lime). In a geological context, they are key indicators of paleoenvironments.

Geological facts

The shell is made primarily of aragonite and calcite. Shells like this have been used as currency (Cowrie shells) and ceremonial trumpets in ancient cultures across the Caribbean and Indo-Pacific.

Field identification & locations

Identify by its spiral whorl pattern and brown 'maculated' spots. Commonly found on beaches throughout the Gulf of Mexico and Atlantic coast. For collectors, look for shells with intact 'lips' or unique color variations.

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