This especially large oyster species produces up to 20-30cm mighty shells, which often display beautiful mother-of-pearl. One differentiates between the Silver-lipped and Golden-lipped Pearl Oyster, depending on the color of the mother-of-pearl towards the rim of the shell. Pinctada maxima can be found in the East Indian Ocean all the way to the tropical west Pacific; especially in Burma, southern Thailand, Indonesia, Philippines and right up to Australian coast. In practically all these areas, pearls are cultured in Pinctada maxima host oysters and are marketed as the widely desired South Sea cultured pearls. It is often forgotten that natural pearls can also grow in these pearl oysters. There are two different color varieties: the White-lipped oyster and the Gold-lipped oyster. These bivalves are the largest pearl oysters in the world. They have a very strong inner shell layer composed of nacre, also known as "mother of pearl". Pinctada maxima oysters grow very large, up to 12 inches in diameter. The two color varieties have different coloration in the outer edge of the interior. This mother of pearl or nacre is responsible for the color of the pearls that the oyster can produce. Water temperature, plankton and sediments determine which color variety is more common in a given area.