produce
a marketable gem and have so far succeeded that a considerable number
have been sold of late in the United States and in many cases the
public buy them not knowing that they are an artificial production. The
base upon which the nacre is deposited appears to be composed of a
substance resembling porcelain shaped like a low dome hollowed out on
the under side and having a hole in the centre of the cavity.
As
there is no nacre on the under side, it must, when the button is placed
in the mussel, be thereby protected from the action of the fish except
at the edges where the nacreous deposit probably joins it to the shell
but in such a manner that it can be easily detached. The pearl covered
button is then fitted to a piece of polished mother-of-pearl of the
same exterior size and shape and the two are neatly joined, forming a
double low domed piece of pearl on one side, and mother-of-pearl on the
other. These Japanese pearls as they are called, when mounted in a
setting constructed to hide the under side, have the appearance of
imperfect spheres of natural pearl.
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