What changed in GIA’s pearl nacre classification?

The change is a classification change, not a new pearl species

GIA’s former nacre result used the broad terms Acceptable and Unacceptable. The current scale uses five ranges—Excellent, Very Good, Good, Fair and Poor—so reports can describe nacre quality with more resolution.

GIA says most pearls that would previously have met expected commercial quality are likely to fall in the Good range. That makes Good a normal classification, not a disguised warning.

What the new nacre scale is looking at

The scale examines structural or textural features at the surface and sub-surface that indicate how continuously nacre formed during growth. GIA also considers post-harvest condition, including wear or damage, alongside trade expectations for thickness.

That distinction matters: nacre condition and continuity are not identical to a direct measurement of nacre thickness. GIA offers average nacre thickness as a separate add-on service for eligible bead-cultured pearls.

• Excellent → least eye-visible nacre variation in the scale
• Good → expected to be common among commercial-quality submissions
• Poor → features or condition that can raise durability concerns

How to use the result when buying

Read nacre beside the other six GIA Pearl Value Factors: size, shape, colour, lustre, surface and matching. A single factor does not turn a report into a price certificate.

For a purchase, keep the laboratory description separate from the seller’s price, return terms, metal quality and provenance claims. The report describes the submitted pearl; the commercial decision still belongs to the buyer.