George Frederick Kunz,
The Book of the Pearl
“ The color of pearls has no connection with the luster. In general it is the same as that of the shell in which they are formed. Black pearls are found in the black shells of Mexico, and pink pearls in the pink-hued Strombus of the Bahamas. Ceylon pearls are seldom of any other color than white, and Sharks Bays are almost invariably quite yellow or straw-colored, while those of Venezuela are commonly yellowish tinged. But from other localities, pearls simulate every tint of the rainbow, as well as white and black. ”
