Tahitian Pearl Classification
Silver, Cream, Brown To Black, Gray, Blue, Green, Yellowish Green, Purple With Green, Rose Overtone.
Appearance, RI, birefringence blink and magnification. A "tooth test" is commonly used in which a pearl is rubbed against a tooth; if gritty, this is an indication that the surface is nacre, versus plastic and glass imitations that feel smooth.
Typical size of Tahitian pearls run 8 to 14mm. They are produced by black-lip mollusk Pinctada margaritifera in French Polynesia.