Pearl Jewelry Guide: Akoya, Freshwater, Tahitian & South Sea Pearls
Complete guide to pearl types, quality grading, and buying tips. Compare Akoya, freshwater, Tahitian, and South Sea pearls on luster, size, color, and value.
Key Takeaways
Pearls are the only gems created by a living creature. A mollusk deposits layers of nacre — calcium carbonate platelets combined with organic proteins — around an irritant inside its shell. Over months or years, this builds the lustrous surface that distinguishes a pearl from any other gem material.
Akoya pearls are the classic round white pearl, produced by the Pinctada fucata oyster in Japan and China. They range from 5 to 10 millimeters — 6 to 8 being most common — and are the roundest of all cultured pearls with the sharpest, most mirror-like luster. A fine Akoya strand of 7 to 8 millimeter pearls typically costs $500 to $5,000.
Freshwater pearls come primarily from China, which produces over 95 percent of the global supply. They are cultured in Hyriopsis cumingii mussels that can produce dozens of pearls per mollusk, making them the best value at $5 to $50 per pearl. Natural colors include white, cream, pink, lavender, and peach, in shapes from round to baroque to coin.
Tahitian pearls are the dark pearls of French Polynesia, produced by the Pinctada margaritifera oyster. They range from 8 to 18 millimeters in naturally dark colors — black, gray, peacock green, aubergine, blue. The peacock overtone combining green and rose iridescence over a dark body color is most prized.
South Sea pearls are the largest at 10 to 20 millimeters, produced by the Pinctada maxima oyster. White pearls come from Australian waters; golden pearls from Philippine and Indonesian waters. They have a satiny, soft luster and fine golden strands can exceed $100,000, making them the most valuable pearl type.
Pearl quality is assessed on luster (sharper reflection equals higher quality), surface (fewer blemishes command premiums), shape (round is most valued, though baroque and keshi are celebrated for uniqueness), size (larger is rarer), and nacre thickness (thicker means better durability). Pearls are soft at 2.5 to 4 Mohs and should be stored separately from harder jewelry. Never use ultrasonic or steam cleaners on pearls.