mineral
Pearl
Aragonite / Calcium Carbonate (CaCO3)
Hardness: 2.5-4.5 (Mohs); Color: White, cream, pink, silver; Luster: Pearly/Iridescent; Crystal Structure: Orthorhombic; Specific Gravity: 2.60-2.85
- Hardness
- 2
- Color
- White, cream, pink, silver
- Luster
- Pearly/Iridescent
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Physical properties
Hardness: 2.5-4.5 (Mohs); Color: White, cream, pink, silver; Luster: Pearly/Iridescent; Crystal Structure: Orthorhombic; Specific Gravity: 2.60-2.85
Formation & geological history
Organically formed inside the soft tissue of a living shelled mollusk as a defense mechanism against irritants. Composed of concentric layers of nacre.
Uses & applications
Primarily used in jewelry (necklaces, earrings, bracelets) and as an ornamental gemstone. Historically used in medicine and cosmetics.
Geological facts
Pearls are the only gemstones in the world to come from a living creature. They do not require cutting or polishing to reveal their natural beauty.
Field identification & locations
Identify by the 'tooth test' (feeling a slightly gritty texture when rubbed against the edge of a tooth). Found in saltwater oysters and freshwater mussels worldwide.
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