Diamonds • Precious Gemstones • Jewelry • Gemology

Most South Sea Pearls are cultured and most are farmed in Australia. Mother of Pearl shells are collected and used to create small spheres called nuclei and, along with pieces of mantle, are implanted into the host shell.

South Sea pearls have thicker layers of nacre than do cultured pearls of other areas.

Distinguishing natural from cultured pearls is done by x-ray.

Australian pearlers do not separate natural from the cultured South Sea Pearls because of the similarity.

Sizes will generally be in the 10 - 15 mm range. Pearls larger than 15 mm are found occasionally, but they are rare and consequently are very valuable.

Cultured Half Pearls are also called "mabe pearls" or "cultured blisters". A hemispherical nucleus is attached to the inside of a shell.

A domed blister forms as the shell secretes nacre. The blister is harvested then backed with mother of pearl.

Mabe pearls tend to be inexpensive and used in moderately priced jewelry.

Keshi are "seedless" pearls that form in the same way natural pearls do, except they are found in shells that are being cultivated at pearl farms rather than in wild shells.

The shell has rejected the implanted irritant but the inserted mantle forms a pearl.

Keshi pearls will have all the properties of natural pearls. Their normal size range is 2 - 10mm.