Pearl

Physical Properties

Hardness: 2.5–4.5 (Mohs scale); Color: White, cream, pink, or silver; Luster: Pearly (iridescent nacrous); Crystal Structure: Orthorhombic microcrystalline; Specific Gravity: 2.60–2.85.

Formation & Geological History

Biogenic formation; produced within the soft tissue (mantle) of a living shelled mollusk. Layers of nacre are deposited around a microscopic irritant over several years.

Uses & Applications

Primarily used in jewelry (necklaces, earrings, rings), cosmetics (pearl powder), and as a traditional gemstone symbols.

Geological Facts

Pearls are the only gemstones made by living creatures. The most famous pearl is 'La Peregrina,' which was owned by Mary I of England and Elizabeth Taylor.

Field Identification & Locations

Identify real pearls by the 'tooth test' (they feel gritty against teeth, while imitations feel smooth). Common locations include the Persian Gulf, waters around Japan, Australia, and French Polynesia.

Identified on: 4/21/2026

Mode: Standard