Guide for Tahitian Pearl Grading

March 3, 2015 by Melissa

Tahitian pearls are well-known for their exotic features and dark colors. Oftentimes called black South Sea pearls, these pearls are harvested in over 80 different natural overtones and colors. However, while grading Tahitian pearls, the Ministry of Perlicultre within French Polynesia defined export standards of grading solely reflective of these considerations: surface/luster and shape.

While a grading factor in assessing additional saltwater pearl types, nacre thickness isn’t any longer considered with Tahitian pearls, as export will be restricted to pearls that have adequate nacre coverage.

There will include 5 shapes of cultured Tahitian pearls. Every pearl exported from French Polynesia falls within one of these categories:

Round: Nearly round or perfectly round shape that has no more than a 2% variation within diameter.

Semi-round: Near round shape which possesses a diameter variance that is greater than 2%, yet less than 5%.

Semi-baroque: The noticeably off-round shape which includes drop, button, oval, and pear.

Baroque: Asymmetrical, irregular shape. By definition, Baroque pearls lack a symmetry axis.

Circles: Over 1/3 of the surface exhibits visible circles considered to be produced by a ‘spinning’ of the nucleus while in pearl formation. If the circles are present yet don’t cover at least 1/3 of the surface, the lines will be graded as inclusions within the surface/luster category.

The next aspect taken into consideration while grading Tahitian pearls includes the luster and surface consideration. Surface will take into consideration the perfection and smoothness of the pearl skin, whereas luster will judge the quantity and quality of light that reflects from the surface of the pearl.

In French Polynesia, the Ministry of Perliculture utilizes a 5-tier grading system that involves grade D, grade C, grade B, grade A, and top-gem. Anything that falls under grade D is refused for export and will be destroyed. The system will correspond to the grading system in the U.S. that includes grade A, grade AA, grade AA+, grade AAA, and gem.

Top Gem: Inclusion-free, perfect surface. Excellent luster.

Grade A: Slight blemishing or perfect which doesn’t exceed 10 percent of the pearl surface. Good luster.

Grade B: The surface blemishing which doesn’t exceed 30 percent of the pearl surface. Medium luster.

Grade C: The surface blemishing which doesn’t exceed 60 percent of the pearl surface. Medium to low luster.

Grade D: The surface blemishing exceeds 60 percent of the pearl surface. Low luster.

Comprehending Tahitian pearl grading allows consumers to make informed decisions while shopping for Tahitian pearls. Upon learning to assess the core grading principles an individual then can decide which additional value factors are most attractive to their personal taste and style. Those value factors involve body size, overtone, and color. While specific colors and bigger pearls are thought to be more valuable, the most precious pearls to you ought to be the ones which fit your personality and style the best.