The South Sea pearl

The colour decided by the lips of the oyster.

Between the Tropic of Cancer and the Tropic of Capricorn — Australia, Indonesia, the Philippines, Myanmar, Borneo — lives Pinctada maxima, a large oyster that produces the pearls which appeared on the market at the end of the 1950s.

Their colour has an anatomical explanation. The inner rim of the shell, which pearl farmers call the lip, tints the nacre the animal deposits: yellowish lips give the golds, which come from the South Seas, silvery lips the whites, which come from Australia. These are the two varieties of the South Sea pearl. The dark gem belongs to a sister oyster, Pinctada margaritifera, and bears the name of Tahitian pearl.

Round pearls start at eight millimetres and reach sixteen, up to twenty-two for the whites; baroques exceed thirty. The sphere, however, remains one case among many: most of the harvest comes out oval, drop, circled or baroque. It is in that proportion that the value of a round South Sea pearl lies.

In the maison's South Sea pearls. Direct selection in Australia for the whites and in the South Seas for the golds · native colour · size measured to the second decimal · every gem admitted only when lustre, shape and structural integrity correspond to the MIMÍ master pearls.

Every South Sea strand is identified by an individual code, which acknowledges its uniqueness.

The seven factors by which a pearl is read: How a pearl is judged. What determines the value of a gem: What determines the price of a pearl.

Text by the MIMÍ Milano gemmologists · updated 9 September 2026