mineral

Queen Conch Shell (Biogenic Calcium Carbonate)

Aliger gigas (synonym Strombus gigas); Composition: Aragonite (CaCO3)

Hardness: 3.5-4.0 (Mohs); Color: Creamy white exterior with a glossy pink to peach interior; Luster: Porcellaneous (china-like) to dull; Crystal structure: Orthorhombic (microcrystalline aragonite); Cleavage: None/Conchoidal fracture; Specific gravity: 2.7-2.9

Hardness: 3
Color: Creamy white exterior with a glossy pink to peach interior
Luster: Porcellaneous (china-like) to dull

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Biogenic formation through accretion by marine gastropods. The shell grows as the animal secretes calcium carbonate from its mantle. These specimens are modern (Holocene) but can be found in Pleistocene fossil records approximately 2 million years old. They form in shallow, warm seagrass beds in the Caribbean and tropical Atlantic.

Uses & applications

Used in the production of cameos (jewelry), as decorative ornaments, musical instruments (horns), and historically for tool making and lime production. The conch pearl is a rare and highly valuable gemstone byproduct.

Geological facts

The Queen Conch shell is famous for its cross-lamellar microstructure, which makes it 1000 times tougher than the mineral aragonite alone. It is a symbol of the Bahamas and is heavily regulated under CITES (Convention on International Trade in Endangered Species) due to overfishing.

Field identification & locations

Identify by its large, heavy spiral shell, flared outer lip (in adults), and characteristic pink aperture. Found commonly in beaches and shallow waters across the Caribbean, Florida Keys, and Bermuda. Collectors should ensure specimens are sustainably sourced and legal to transport across borders.

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