South Sea pearls come from Pinctada maxima, the largest pearl-producing oyster. The pearls measure 9 to 20 mm, with most falling between 12 and 16 mm. The main farming regions are north-western Australia, Indonesia and the Philippines. The silver-lipped variety of the oyster produces white and silver pearls, the gold-lipped variety golden ones.
Culturing takes a long time. After the nucleus is implanted, the oyster remains in the sea for 2 to 4 years, and each oyster carries only one pearl per cycle. The nacre grows to 2 mm and thicker, hence the soft, satin-like lustre that differs from the sharp mirror of the Akoya. Only 10 to 30 percent of a harvest is round or near-round.
Size, the rarity of round pieces and the long culturing period make the South Sea pearl the most expensive type of cultured pearl. What a necklace costs is covered in the article Pearl necklace: cost by pearl type.
