South Sea pearls are among the largest commercially harvested cultured pearls in the world. The average size of a South Sea pearl is 13mm, with most harvests producing a range of sizes from 9mm up to 20mm.

The South Seas lie between the northern coast of Australia and the southern coast of China. These waters are the native habitat of the large oyster, the Pinctada maxima. This oyster grows up to 12 inches in diameter, and can be nucleated with a much larger bead than other saltwater oysters such as the Akoya.

There are two varieties of Pinctada maxima: the silver-lipped and the gold-lipped. The two are distinguished by the coloration of the outer edge of the interior. This shell is also known as mother-of-pearl, and is responsible for the coloration of the cultured pearls produced.

Unlike the Akoya oyster, the South Sea oyster will only accept one nucleation at a time. The oyster is nucleated when it is only about half developed, from 4.7 inches to 6.7 inches in size, or about 24 months old. Although the South Sea oyster will only handle one nucleus at a time, this oyster (like the tahitian pearl producing Pinctada margaritifera) can be nucleated up to three times over the course of many years.

There are four reasons South Sea pearls can grow to such large sizes dwarfing many of their other saltwater pearl counterparts. The reasons consist of: the large size of the Pinctada maxima, the size of the implanted bead, the length of time the pearl is left to grow in the oyster, and the oyster’s environment. Due to the size of the oyster it is able to accept a large bead. The gonad of the Pinctada maxima is several times larger than that of the Akoya. Because of this same reason the South Sea oyster deposits nacre around the nucleus at a much quicker rate, especially in warm water which speeds the oyster’s metabolism. The South Seas are also extremely clean, and filled with plankton – the Pinctada maxima’s favorite food source. The clean waters and abundant food supply also speeds the nacre production. The growth period for South Sea pearls is also substantially longer than that of the Akoya. Akoya pearls are harvested after only 9-16 months, where as South Sea pearls are harvested after at least 2 years.

South Sea pearls have several distinct characteristics that are unique to this gem. The nacre is unusually thick, ranging from 2-6mm compared to the .35-.7mm of an Akoya pearl. South Sea pearls also have a unique, satiny luster that comes from the rapidly deposited nacre and warm waters of the South Seas. South Sea pearls also have a subtle array of colors, typically white, silver, and golden, that are rare in other pearl types