Pearl
Natural/Cultured Pearl (Biogenic Mineraloid) · Organic Gem
Crystal System
Orthorhombic (as aragonite crystals)
Mineral Group
Carbonates (Biogenic)
Chemical Formula
CaCO3 (Calcium Carbonate) with conchiolin and water
Formation Process
Biogenic formation. Pearls form when a mollusk (such as an oyster or mussel) secretes layers of nacre (mother-of-pearl) around a microscopic irritant or a surgically implanted bead as a defense mechanism.
About This Crystal
The specimen consists of a matched strand of near-spherical white to cream-colored cultured pearls displaying a characteristic iridescent luster. The individual pearls show fine orient, smooth tactile surfaces with subtle overtones, and are individually knotted on a silk cord terminating in a gold clasp.
Physical Characteristics
Body color ranges from white, cream, and silver to rosé, with typical pearlescent iridescence. Streak is white. Pearls possess no cleavage and exhibit a splintery to uneven fracture. Specific gravity is approximately 2.65 to 2.78. Tenacity is tough due to the interlaced nacre structure, and pearls generally fluoresce a soft blue or yellow under longwave UV light.
Optical Properties
Pearls are doubly refractive with a refractive index ranging from 1.530 to 1.685. They exhibit characteristic luster known as orient or iridescence, caused by the interference and diffraction of light from overlapping microscopic layers of aragonite platelets.
Hardness & Durability
Origin Region
Saltwater pearls are commonly sourced from the Persian Gulf, the South Sea (Australia, Indonesia, Philippines), Tahiti, and Japan. Freshwater pearls are primarily farmed in China and the United States.
Hardness & Durability
Mohs hardness is relatively low, typically 2.5 to 4.5. Pearls have low durability compared to traditional gemstones, making them susceptible to scratching by metals, harder stones, and even dust. They are sensitive to acids, cosmetics, perfumes, and perspiration.
Care & Maintenance
Clean gently with a soft, damp cloth after wearing. Never use ultrasonic cleaners, steam cleaners, or harsh chemical detergents. Store flat in a soft pouch or lined box away from harder jewelry items. Apply perfumes and cosmetics well before putting on pearl jewelry.
Rarity & Value
Value varies widely depending on whether the pearls are natural or cultured, size, shape, color, luster, surface flawlessness, and matching. High-grade South Sea or Akoya saltwater pearls command significant premium prices, while common freshwater pearls are more accessible. Bleaching and dyeing are common treatments for lower-grade farmed pearls.
Special Characteristics
Pearls exhibit a unique optical phenomenon called 'orient' or 'iridescence,' which is the shimmering play of rainbow colors produced by the light diffraction across microscopic aragonite crystal platelets comprising the nacre.
Lore & History
Pearls have been prized as symbols of purity, wealth, and wisdom for thousands of years across ancient civilizations including Rome, Egypt, and China. Historically associated with the moon and water, they are traditionally linked to the sacral and third-eye chakras in metaphysical practices, believed to promote calming, sincerity, and emotional balance.