💎 Diamonds & GemsUpdated: September 2, 2026

Cultured Pearl Grading: Akoya, White South Sea, Tahitian & Nacre Thickness

Reviewed by Gemological Appraisal & Fine Jewelry Review Board

Executive Gemological Summary

Evaluating organic gems: luster sharpness, orient, surface blemish grading (AAA-to-A), baroque silhouettes, and silk thread restringing intervals.

Unlike crystalline gemstones, pearls are organic gems produced by living mollusks, evaluated primarily by luster intensity, nacre thickness, and surface perfection.

1. Cultured Pearl Varieties Compared

Pearl VarietyMollusk SpeciesAverage DiameterCharacteristic Luster & Overtones
Japanese AkoyaPinctada fucata martensii6.0mm – 9.0mmMirror-like metallic sharpness; rose/silver overtones
White & Golden South SeaPinctada maxima9.0mm – 16.0mm+Deep satiny glow; rich champagne and golden tones
Tahitian Black PearlPinctada margaritifera8.0mm – 14.0mmPeacock green, aubergine, and graphite dark bodycolor
Freshwater (Edison)Hyriopsis cumingii7.0mm – 15.0mmWide pastel palette (lavender, peach); durable solid nacre
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Gemological Appraisal & Fine Jewelry Review Board

Monographs and valuation criteria are reviewed by GIA Graduate Gemologists and USPAP-compliant certified jewelry appraisers.

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