Varieties of Pearl
The Oriental pearl is distinguished by its mellow skin and the soft tones which appear, whatever the color.
fresh-water pearl, even at its best, is characterized by a slightly
chalky appearance, and harshness as compared with the Oriental.
or conch pearls, pink to pale yellow and white, having a peculiar wavy
sheen, are distinguished by a hard china-like lustre. They are found in
the Gulf of California, and off the coasts of Mexico and West India
pear, and egg-shape pearls are formed within the oyster, and are not
attached to the shell, the nucleus of their successive skins of nacre
being within themselves.
Button pearls are those having a flat underside.
Baroques are irregular and odd-shaped pearls.
Wing pearls are long and slim, resembling the closed wing of a bird, and are attached at some point to the shell during formation.
pearls are excrescences raised on the inner side of the shell by the
oyster in its effort to exclude a parasite which has intruded or bored
its way through the shell.
In all cases, pearls are successive layers of nacre deposited by the oyster over a nucleus of foreign substance.