Black Pearl (Tahitian Pearl)

Physical Properties

Hardness: 2.5 - 4.5. Color: Black, grey, or silver with peacock, green, or purple overtones. Luster: Pearly to metallic. Crystal structure: Orthorhombic (microcrystalline). Cleavage: None. Specific gravity: 2.60 - 2.85.

Formation & Geological History

Formed organically within the Pinctada margaritifera oyster. This biomineralization process occurs when the mollusk coats an irritant with layers of nacre. While they are organic gems, they are classified as mineraloids in geology.

Uses & Applications

Primarily used in high-end jewelry (rings, necklaces, earrings) and as collector specimens for gemstone enthusiasts.

Geological Facts

Unlike white pearls which are often bleached, Tahitian black pearls get their dark color naturally from the organic pigments in the oyster. They are often called 'Queen of Pearls'.

Field Identification & Locations

Identify by checking for natural surface irregularities and the 'tooth test' (feels gritty against teeth) to distinguish from smooth plastic imitations. Real pearls show deep, multi-colored overtones rather than a flat surface color.

Identified on: 4/21/2026

Mode: Standard