far more abundant than the elusive, rare, and larger south sea pearl oyster Pinctada maxima, which cannot be found in lagoons, but which must be dived for in a rare number of deep ocean habitats or grown in hatcheries. Natural black pearls are rare, with black pearls having a body color that may be assessed as silver, silver blue, gold, brown-black, green-black, or black. Black cultured pearls from the black pearl oyster – Pinctada margaritifera – are not South Sea pearls, although they are often mistakenly described as black South Sea pearls. In the absence of an official definition for the pearl from the black all use to, these pearls are usually referred to as "black pearls". The correct definition of a South Sea pearl – as described by CIBJO and GIA – is a pearl produced by the Pinctada maxima pearl oyster. South Sea pearls are the color of their host Pinctada maxima oyster – and can be white, silver, pink, gold, cream, and any combination of these basic colors, including overtones of the various colors of the rainbow displayed in the pearl nacre of the oyster shell itself. South Sea pearls are the largest and rarest of the cultured pearls – making them the most valuable. Prized for their exquisitely beautiful 'orient' or lustre, South Sea pearls are now farmed in various parts of the world where the Pinctada maxima oysters can be found, with the finest South Sea pearls being produced by Paspaley along the remote coastline of North-Western Australia. White and silver colored South Sea pearls tend to come from the Broome area of Australia, while golden colored ones are more prevalent in the Philippines and Indonesia. A farm in the Gulf of California, Mexico, is culturing pearls from the black lipped Pinctada mazatlanica oysters and the rainbow lipped Pteria sterna oysters. Also called Concha Nácar, the pearls from these rainbow lipped oysters fluoresce red under ultraviolet light. From other species Biologically speaking, under the right set of circumstances, almost any shelled mollusk can produce some kind of pearl. However, most of these molluskan pearls have no luster or iridescence. The great majority of mollusk species produce pearls which are not attractive, and are sometimes not even very durable. Such pearls usually have no value at all, except perhaps to a scientist or collector, or as a curiosity. These objects used to be referred to as