mineral

Abalone Shell (Mother of Pearl)

Aragonite (Biogenic Calcium Carbonate, CaCO3)

Hardness: 3.5-4.0; Color: Multicolored iridescence (blue, green, pink, purple); Luster: Pearly/Nacreous; Crystal Structure: Orthorhombic (microcrystalline layers); Specific Gravity: 2.7-2.9

Hardness: 3
Color: Multicolored iridescence (blue, green, pink, purple)
Luster: Pearly/Nacreous

Identified April 9, 2026More mineral →

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Physical properties

Hardness: 3.5-4.0; Color: Multicolored iridescence (blue, green, pink, purple); Luster: Pearly/Nacreous; Crystal Structure: Orthorhombic (microcrystalline layers); Specific Gravity: 2.7-2.9

Formation & geological history

Biogenic formation; produced by the mantle of abalone mollusks as an inner shell layer. The alternating layers of aragonite and conchiolin create light interference, resulting in iridescence. Geological age: Holocene (Modern).

Uses & applications

Used extensively in jewelry, decorative inlays for musical instruments (guitars), furniture ornamentation, and various buttons/clothing accessories.

Geological facts

The structural strength of nacre is approximately 3000 times tougher than the mineral aragonite itself due to its unique 'brick and mortar' microscopic architecture. It is often referred to as 'sea opal.'

Field identification & locations

Identify by its unique wavy, iridescent color patterns and the typical ear-shaped curve of the shell. Commonly found along the coastal waters of California, Mexico, Japan, and New Zealand.

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