The morning call., 1894-07-08

OPALs-H. e.. City. The opal is a natural
form OF hydratia silica which has apparently
hardened from a gelatnous state. 1t differs
from quartz in containing from 3 TO 10 per cent
or water, lis only other essential constituent
being silica, though little alumna oxide of
iron, etc., being present In some varieties 1t
has never been found crystalized and it does
not exhibit crystalline structure like quartz.
The most beautiful variety Is known as the
noble or precious opal. 1t is remarka Dle for lis
play OF iridlscent colors. their rainbow tnts be-
ing flashed from small fakes forming sort OF
polychromatic mosaic. Another very beautiful
opal is the harlequin, so called because the
cOlors are not equally diifused, but are in de-.
tached spots. In other kinds OF Opals cOlors
are disposed Is broad bands The tints vary
with the angle ana the relative position Of the
stone and The observer, so that by moving the
opal brilliant succession OF flashes of fire may
be obtained. The noble opal In consequence OF
its brilliant iridiscence is valued as orna-
mental stone 1t is displayed to the best ad-
vantage when cut with convex surface. The
most valuable opais that are offered on the
markets are principally from Hungary Many
beautiful gems come from Queensland, the
United States and Mexico. AT one time the
opal sold from 81 TO $40 carat, but now the
value Is fixed according 10 the perfectness OF
the colors. One of ten carats might bring only
So, while another OF exactly the same weight,
but perfect in the play of colors, would bring
$4,000. The gem is no longer sold by weight,
but is rated according to size and brlliancy
In other words. its value Is what an individual
wishes 10 pay TO possess 1t. Formerly 1t was
believed that the opal possessed magic power,
as the comforting OF lnviSibllty on the pOsSessOr
who wrapped the gem In bay-leaf The an
clients called the opal ceraunlum, from notion
that 1t was thunder stone. Some years ago
some one started story, which found its way
Into print and was widely copied, to the effect
that the opal was an unlucKy stone and that
the wearer was always beset with misfortune.
This gained such a hold on the people. the
world over, that but very few were bold enough
To wear one and 0pals became drug on the
marNet When it became known that Queen
Victoria was partial TO Opais tile superstition
began TO yied and at this time IL is receiving
It's share OF popular favor. 1t Is related tnat Il
Roman Senator preferred exile to giving up a
opal. seen In the days OF Pliny, was valued
al S500,000. AT the exposition OF 1851 there
was exhibited from Hungary an opal weighing
526R carats, which was valued at $4,000
In the crown jewels OF France were two opals
that were worth $4,000 francs. The various
kinds of opas are: CLASSY opal Or Muler's
glass, transparent, colorless aud very CLASSY,
fire opal or giras0l, transparent, brilliant, W.T.
reOus, bright hyacnth or yellow; noble, lnclud.
ing the harlequin, semi-transparent or trans
lucent. reslnous, inclinlng 10 vltrrous. blush
or yellowish white with brilliant prsmatlc
coors. showing double refracion: common
opals, semi-transpareDi, vitreous, white, yellow
green, red and brown wood opal or lithoxyOn.
with the form aud texture OF wood distinctly
seen; opal jasper, blood, brown or yellow.
cacholong, opaque, dull, glimmering or peary
and yell0wish or rarely reddish white; silice0us
sinter, deposited from the geySers or other hot
springs. Many opals. trealed with a solution
OF potash, leave crystals. and where such are