mineral
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
Hardness: 2.5-4.5 (Mohs), Color: White, cream, pink, silver, or black, Luster: Pearly (orient), Structure: Amorphous/Orthorhombic (Aragonite)
- Hardness
- 2
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Physical properties
Hardness: 2.5-4.5 (Mohs), Color: White, cream, pink, silver, or black, Luster: Pearly (orient), Structure: Amorphous/Orthorhombic (Aragonite)
Formation & geological history
Produced within the soft tissue (mantle) of living shelled mollusks; formed via concentric layers of nacre around an irritant.
Uses & applications
Primarily used in jewelry (necklaces, earrings, rings) and as a decorative organic gemstone; historically used in cosmetics.
Geological facts
Unlike other gemstones, pearls are organic and require no cutting or polishing to reveal their natural beauty. They are the birthstone for June.
Field identification & locations
Identified by their unique 'orient' (iridescence) and the 'tooth test' (gritty texture on teeth). Found in freshwater rivers and saltwater oceans globally.
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Mineral
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