stone is moved about, as then a fine opal really appears to have an actual life within itself.
They
are very brittle, and are always much more brilliant on a warm day. A
dealer in precious stones, aware of this peculiarity, invariably holds
an opal in his hand before showing it, in order to impart warmth to the
gem. Fine stones of large size are rarely found; they seldom exceed an
inch in diameter. At the mines in the locality of Gracias a Dios, in
Honduras, specimens have been found equally as fine as the Hungarian
stones, and certainly not to be distinguished from specimens coming
thence.
The
hydrophane, or Mexican opal, loses its beauty when exposed to water,
and Sir Walter Scott has alluded to this fact in 'Anne of Geierstein,'
although in that romance he ascribes it to supernatural agency. Strange
to say, after the publication of the brilliant novelist's fiction, the
belief that opals were unlucky obtained such currency that they
quickly went out of fashion. Of late years they have again come into
vogue, and now promise to become, as they have always deserved to be
esteemed, universal favourites; the more especially as they are the only precious stones which defy imitation. In
Eastern^ nations they have always been highly prized. The Mexican opal
can be restored to its original colour by a moderate application of
heat.
The common opal is used in Germany for cheap jewellery—cane-tops, snuff-boxes, etc.; the other varieties are not used. The value of the precious opal depends
