South Sea Pearls: These pearls are among the rarest of all pearls that are available. These pearls are cultivated in the ocean waters located around Australia. They come in natural colors including white, pink, silver, gray, and gold. They range in size from 8mm to 22mm. The values of these pearls are generated from the rarity and quality. The qualities of the pearls are measured by the pearls luster, surface flaws, shape, color and size.