soft
velvety luster of the oriental mother-of pearl, and fresh-waters, like
the lining of the unio, have a somewhat thinner looking and more chalky
texture.
Abalone
pearls have the irregular surface and coloring of the haliotis. Conch
pearls resemble the delicate pink china-like lining of the shell, and
clam pearls have the glazed earthenware appearance of the inside of a
clam shell. The one material difference between a pearl and the lining
of the shell in which it grows is, that in the one case the fish
deposits the nacre over an even surface, and in the other wraps it
around a central point with delicate precision in successive filmy
layers.
Dissection
shows that a pearl during growth is liable to many mishaps. As with the
human creature, a promising youth may end in a wretched maturity. It is
also possible that an ugly period may be redeemed by later happenings,
and the thing that was worthless in its early existence, be found in
its age worthy of a place among the great gems. Pearls found with a
dull, chalky exterior sometimes have lustrous skins beneath. Sometimes
a bony-
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