mineral

Pearl

Calcium Carbonate (primarily Aragonite and Calcite), CaCO3

Hardness: 2.5–4.5 (Mohs); Color: White, cream, pink, silver, black; Luster: Pearly (iridescent); Crystal structure: Orthorhombic (aragonite); Specific gravity: 2.60–2.85

Hardness: 2
Color: White, cream, pink, silver, black
Luster: Pearly (iridescent)

Identified May 3, 2026More mineral →

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Physical properties

Hardness: 2.5–4.5 (Mohs); Color: White, cream, pink, silver, black; Luster: Pearly (iridescent); Crystal structure: Orthorhombic (aragonite); Specific gravity: 2.60–2.85

Formation & geological history

Organic origin; formed within the soft tissue (mantle) of a living shelled mollusk. Layers of nacre are deposited around an irritant (natural) or an implanted nucleus (cultured).

Uses & applications

Primarily used in jewelry (earrings, necklaces, rings) and high-end fashion accessories. Finely ground pearl powder is also used in some cosmetics and traditional medicines.

Geological facts

Pearls are the only gemstones produced by living creatures. Unlike mineral gemstones that are mined, pearls require no cutting or polishing to reveal their natural beauty.

Field identification & locations

Identify by the 'tooth test' (feels gritty when rubbed against the edge of a tooth, whereas fakes feel smooth). Real pearls also show subtle variations in shape, surface texture, and overtone colors.

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