Pearl

Physical Properties

Hardness: 2.5-4.5 (Mohs scale); Color: White, cream, silver, pink, black; Luster: Pearly (iridescent); Structure: Amorphous (microcrystalline aragonite); Specific gravity: 2.60-2.85

Formation & Geological History

Biogenic formation within the soft tissue (mantle) of a living shelled mollusk. It is formed by the secretion of nacre around an irritant.

Uses & Applications

Primarily used in jewelry (necklaces, earrings, rings) and as a traditional gemstone in various cultures.

Geological Facts

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

Field Identification & Locations

Identify by the 'tooth test' (feels gritty against teeth) or by checking for concentric growth layers under magnification. Found in marine and freshwater environments worldwide.

Identified on: 5/1/2026

Mode: Standard