gemstone

Pearl

Calcium Carbonate (Aragonite/Calcite) with Conchiolin

Hardness: 2.5-4.5 on the Mohs scale, Color: White, cream, silver, grey, blue, yellow, lavender, or black, Luster: Pearlescent (chatoyant/iridescent), Crystal Structure: Orthorhombic (microcrystalline aragonite platelets), Specific Gravity: 2.60-2.85

Hardness: 2

Identified August 2, 2026More gemstone →

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Physical properties

Formation & geological history

Formed organically within the soft tissue (specifically the mantle) of a living shelled mollusk, as a defense mechanism against an irritating foreign object.

Uses & applications

Used primarily in fine jewelry, necklaces, rings, earrings, and bracelets.

Geological facts

Unlike most gemstones that are mined from the earth, pearls are organic gems produced by living marine or freshwater organisms.

Field identification & locations

Identified by its distinctive organic luster and relative softness; commonly cultured in oceans and freshwater lakes globally, especially in Japan, China, Australia, and the South Pacific.

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