... off-round, tear-drop, button, flat pearl, baroque pearl, keshi pearl, biwa pearl; flower-shape pearl and so on· Packing : It's ok ... pearlescent substance in order to imitate the natural iridescence of nacre or mother of pearl. Varieties of imitation pearls ... French pearls, Bourguignon pearls and Venetian pearls.Mother-of-pearl pearl: crushed nacreous shell powder, sintered into the desired shape ...