The
best Moonstones come principally from Ceylon. This stone is known also
by the name of Ceylon Opal; it is a variety of felspar, or orthoclase,
containing as its main chemical constituents silica (two-thirds per
cent), alumina, and potash; therefore when remedially worn it is
specially adapted by nature for persons to whom silica (flint) is
likely to prove useful, as described here under that heading.
The
Moonstone is, popularly speaking, so named because of the play of light
which it exhibits. The scientific name of the mineral is " Adularia,"
from Adula, the summit of a Swiss mountain-peak, (St. Gothard).
The Moonstone, a
romantic tale, (" tail out of his own head," as Tom Hood said of the
tadpole), was told by Wilkie Collins, in 1868. It is founded—as stated
in the original preface—in some important particulars, on the stories
of two of the royal diamonds of Europe, " the magnificent stone which
adorns the top of the Russian Imperial Sceptre, and which was once the
eye of an Indian idol; and the famous Koh-i-noor, (which is also
supposed to have been one of the sacred gems of India, and, further, to
have been the subject of a prediction prophesying a succession of
misfortunes to the persons who should divert it from its ancient
uses)." Towards enhancing the interest, and importance of his story
the author, allowably enough, supposes the Moonstone to have been a
Diamond, which, as we now see, is not really the case. This famous "
Yellow Diamond " (the moonstone), according to the earliest known
traditions, had been set from time immemorial in the forehead of the
four-handed god who typifies the moon. Partly from its colour, and
