LUSTER OF SOUTH SEA PEARLS

Lustre refers both to a pearl's brilliance -- the way its surface reflects light -- and its inner glow: the way it refracts light.

The nacre coating of South Sea pearls is especially thick, giving them a soft yet deep, rich lustre unlike that of any other type of pearl. Their lustre may be referred to as "satiny," less "mirror-like" than that of Akoya pearls. South Sea pearls also possess a beautiful soft iridescence found only in pearls with exceptionally thick nacre.