Black South Sea pearls have a certain edgy and mysterious look because of their iridescent metallic sheen and darker colour. Despite their name, the pearls, also known as Tahitian pearls, are available in a broad array of colours, including dark greenish black, silvery grey, light purple and yellow.
They also come in different sizes and shapes. This versatility makes black pearls an ideal material for unconventional jewellery designs.
Most black pearls are from Tahiti in French Polynesia and some are cultured in New Caledonia and New Zealand, says Tom Takada, merchandising manager of Mikimoto Pearl Jewellery (HK). The peacock green colour is highly desirable, he says.
Tahitian pearls are created in the womb of the special black-lipped mollusk, which is indigenous to French Polynesian waters, known as the pinctada margaritifera, or black-lip mother-of-pearl. This mollusk naturally secretes a dark pigment which, depending on the quantity, gives the resulting pearl a basic colour ranging from black to grey, according to Perles de Tahiti GIE, an organisation based in French Polynesia which promotes Tahitian pearls worldwide.
Rene Hodel, CEO of pearl jewellery brand Hodel, says Tahitian black pearls rarely reach the size of white South Sea pearls due to the smaller size of the mollusks that produce them. Most black pearls are from 6mm to 16mm in diameter, Hodel adds.
Many of the Tahitian pearls are actually silver and charcoal in colour, some with hints of green. These pearls are natural products, but their cultivation has been under threat from climate change.