THE OPAL
T
HE precious opal is
one of the most individual of gems; of all the opaque minerals, it
reveals the most beautiful play of colours, in folklore it is the
birth-stone of October and the symbol of hope, and yet, for years, the
fame of this fire-flashing stone was blackened by a cloud of
superstition which condemned it as unlucky; a superstition the origin
of which is obscure. For a time, however, it largely regained its lost
popularity, having found its most illustrious patron in Her Majesty,
the late Queen Victoria. Another remarkable fact about the opal is that
it is not found in the Orient—the very land of gems.
Opal, in mineralogy, is Hyalus opalinus, of
the order Hyalina; it is of granular structure; small reniform and
stalactitic shapes and large tuberose-like concretions; hardness 5.5 to
6.5; specific gravity 2 to 2.21; lustre vitreous, sometimes inclining
to resinous or pearly; streak,
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