mineral

Tahitian Black Pearl

Biogenic Calcium Carbonate (Aragonite/Conchiolin Mixture), CaCO3

Hardness: 2.5–4.5; Color: Black, charcoal, or dark green with peacock/iridescent overtones; Luster: Pearly to metallic; Structure: Orthorhombic (microcrystalline); Cleavage: None; Specific Gravity: 2.60–2.85

Hardness: 2
Luster: Pearly to metallic

Identified April 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed within the Pinctada margaritifera (black-lipped oyster) by secreting nacre over an irritant or nucleus. Most modern specimens are from aquaculture in French Polynesia.

Uses & applications

Primarily used in high-end fine jewelry, such as rings, necklaces, and earrings; also highly sought after by gemstone collectors.

Geological facts

Tahitian pearls are one of the most exotic pearls in the world; unlike white pearls, their dark color is natural and not the result of dyeing. They are often called 'Black Pearls' but exhibit a kaleidoscope of colors.

Field identification & locations

Identify by 'tooth test' (gritty surface feel), weight, and unique peacock iridescent overtones. Found in the lagoons of the Tuamotu Archipelago and Gambier Islands.

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Mineral/Rock

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mineral