What gives pearls their different colors?
A pearl s natural color depends mainly on the species of mollusk involved. The color of the pearl tends to match the inside of the mollusk s shell black pearls are made by the Black-lipped Pearl Oyster, gold pearls are produced by the Silver- or Gold-lipped Pearl Oyster, etc. The pigment resides in the organic layers, between the layers of aragonite, a crystalline form of the mineral calcium carbonate. However, artificial coloring is not unknown in the pearl trade. Suppliers may dye, bleach, or irradiate pearls to alter their color.
