Cultured mainly by the Pinctada Margaritifera oyster in the salt waters of French Polynesia—not in Tahiti, despite the name—these pearls are not always black. Their color range runs from greys with green, orange, magenta or golden iridescence to intense cobalt blues. The cultivation time is 2 to 3 years. Oyster survival rates are low, and most pearls produced have significant surface imperfections, so flawless pearls command high prices in the jewelry market. These pearls range in size from 8 to 18 mm.
They come from the saltwater Akoya oyster—Pinctada Fucata—and are cultured in Japan and China. They are the most difficult pearls to grow: only about 5% of large spherical implants end up producing a quality pearl over 7 mm with near-perfect roundness. These pearls are known for their almost perfect roundness and intense iridescence, with tones that vary depending on the cultivation process, producing white, pink and cream varieties.
Freshwater pearl farming is widespread in China, Japan and the United States. They are obtained from the Ikekou mollusk—Unio Margaretafera Oyster—and also from Hyriopsis cumingii, both freshwater species that can produce four or more pearls at the same time, in different colors and shapes. They require a cultivation time of 3 to 8 years. Since the 1990s, Freshwater pearls have dramatically improved in quality, becoming a real alternative to the classic Akoya shell-nucleated pearls on the market, alongside other more select types such as Black Tahitian pearls or Australian pearls. Freshwater pearls are characterized by their high nacre content and their diversity of shapes, colors and sizes, reaching up to 16 mm.
They are cultured in the salt waters of northern Australia and Southeast Asia by the Pinctada maxima oyster. They are considered among the most expensive pearls. They stand out for the depth of their luster and their silvery iridescence, reaching sizes between 9 and 27.9 mm.
