The Surface Quality & Category Top Gem
This is determined by observing the special features of the pearls surface and its lustre. Surface feature is measured according to the importance of the surface, smooth and without imperfection. Also some imperfections can be seen on the surface of the pearl, such as: punctures, streaks, stripes, cracks, holes, organic deposits, calcite deposits or devitalised areas; are considered to be any flaw in the nacre that is visible to the naked eye such as pits, bumps, scratches, deposits, ridges and cracks. Lustre is evaluated according to the reflection of the light on the pearlʼ’s surface. The brighter is the reflection, the higher is the lustre. Hence, a good lustre corresponds to a total reflection of the light, creating a mirror effect. A pearl without lustre corresponds to a dull aspect of its surface. A Top gem pearl, is one with a high lustre, and a flawless surface. When harvesting pearls, the pearl farmer performs an initial sorting of this crop, discarding all the rejects. He then performs a more detailed separation of his crop sorting out pearls by size, shape and category.Tahiti Cultured Pearlʼs diameter is expressed in millimeters, rounded to the inferior unity.
Tahiti Cultured Pearlʼs weight is measured in grams.
Tahiti Cultured Pearlʼs shapes are classified as follows:
• Round
• Semi-round
• Drop
• Button
• Semi-baroque • Baroque
• Circled
The main colour of the pearl must be as homogenous as possible. Generally a pearl has one or several colour hues. Color, the range of pearl necklaces or pearl pairing, enabling a subjective evaluation of the Tahitian cultured pearl enable a subjective assessment of the Tahitian cultured pearl.
Round pearls (R) are almost-perfect spheres whose diameter variation rate is less than 2% of the smallest diameter.
Semi-round pearls (SR) are slightly imperfect sphe- res whose diameter variation rate is greater than 2% but less than 5% of the smallest diameter.
Drop or pear pearl (DR), oval (OV), presenting at least one axis of symmetry.
Button pearl (BT), presenting at least one axis of symmetry.
Semi-baroque pearls (SB), in a strict sense, presenting at least one axis of revolution.
Baroque pearls (BQ) are characterised by irregular shapes.
The ringed or circled pearl (CL) has at least one con- centric ring or circle, in the shape of a streak or con- cave ring, located beyond the upper or lower third part of the surface of the pearl, whatever its original shape. When the ring(s) is/are located in the upper or lower third part of the pearl, the pearl is classified in the category of its original shape without taking into account the ring(s). The same applies for diametri- cally opposed rings, which do not occupy more than one third of the surface of the pearl.

Category A
An “A category”, is a flawless pearl on at least 90% of its surface and on the missing 10%, the pearl may have some slight concentrated imperfections. The pearl has at least a very high lustre.
Category B
A “B category”, is a flawless pearl on at least 70% of its surface, on the missing 30%, the pearl may have some slight concentrated imperfections with one or two deep imperfections tolerated. The pearl has an average lustre.
Category C
A “C category”, is a flawless pearl on at least 40% of its surface, on the missing 60%, the pearl may have some slight concentrated imperfections with a 10% of deep imperfections tolerated. The pearl has a minimum average lustre.
Category D
A “D category” is a pearl having slight flaws on at least 60% of its surface, with a minimum tolerance of at least 20% of deep imperfections and/or white punctures. The pearl has a poor lustre.
By definition, this pearl is entire. Its pearl layer has a sufficient thickness, which does not make the nucleus appear, even by transparency. Since 1st July 2002, the legal thickness of the nacre layer between the nucleus and the external surface must be at least 0,8 mm thick. Any pearls that do not satisfy these criteria may not be called a “Tahiti Cultured Pearl” and will be deemed as reject. A reject, even produced in French Polynesia by the pearl oyster Pinctada margaritifera var. cumingii is:
- a cultured pearl presenting either calcite layers, or organic layers, or both, on more than20% of its surface; - a cultured pearl presenting devitalised areas visible on more than 20% of its surface; - a pearl that does not present the regulate thickness; - a pearls whose nucleus is visible to the naked eye. Both commercialisation and exportation of rejects are prohibited in French Polynesia.