South Sea Pearl Classification
South Sea Pearl
Gray, White, Cream, Yellow, Pink, Purple With Blue, Green 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 a South Sea pearl runs 10 to 15mm; They are produced by silver and gold lipped Pinctada maxima mollusk.