Tahitian pearls, or black pearls, are unique because they are produced in only one place in the world: in the lagoons of French Polynesia.
 

The Tahitian pearl is produced in Pinotada, Margaritifera or Black-lip perl. Black-lip shells are grown in French Polynesia, Cook Islands, Micronesia and to some extent even in Japan, Thailand and the Philippines. But only those grown in French Polynesia can be called Tahitian pearls. These pearls have a remarkable range of colours from light cream to white to deep black. Unlike the black freshwater, dyed or irradiated Akoya pearls, Tahitian pearls have a completely natural dark colour. The smallest possible thickness of the pearl, which is permitted in French Polynesia by law, is 0.8 mm.

The Tahitian pearl is one of the largest pearls in the world, the only larger industrially harvested pearls are the South Pacific pearls.

Size: 8 - 18 mm

 

Shape: Artificially made pearls - perfectly round
Natural pearls - round / semi-round, oval, ring, baroque, drop shape


Colour: black, cherry, purple, cream, rainbow, peacock green, metallic gray

Gloss: It is influenced by the degree of light penetration on the surface - the most valued are those on which light is reflected, like a mirror

 

 

Sources used:
The Pearl Book - The Definitive Buying Guide. (2008). 4th ed. Woodstock: GemStone Press, pp. 38-62.
Pearl-guide.com. (2016). South Sea and Tahitian Pearl Grading. [Online] Available at: http://www.pearl-guide.com/forum/content.php?94-South-Sea-and-Tahitian-Pearl-Grading [Accessed 10 Nov. 2016].