The copper country evening news. [volume] (Calumet, Mich.) 18??-1907, 1897-05-08
ITO BE COntinued.)
GEMS HAVE DISEASES.
Some Lose Color, Some Gradually Fadx
and Die, Others Chip and Crack.

Some Lore Color, Some Gradually Fadx
and Die, Others Chip and Crack.
Gems have diseases just as men and
women do, with this difference, that the
infirmites of precious stones can rarely
be cured Some gems observation-disclosures
old in other words--and gradually become
lifeless. Pearls are most subject To this
fate and no means have been found to re-
store them to life.
Among infirmities to which precious
stones are liable Is one common to all col
ored stones, that of fading or losing color
when long exposed to the light The en-
erald, the sapphire and the ruby suffer the
least, their colors being as nearly perna-
nent as colors can be, yet experiments
made a few years ago in Paris and Berlin
to determine the deterioration of colored
gems through exposure showed that even
these suffered, II ruby which had lain for
two years in u show window being perccp-
tibly lighter i'm tint than its original mate,
which was kept in the darkness.
The causes of the change are not very
clear, even to expert chemists, but 1t is
evident that the action of the light on the
coloring matter of the gem effects "A detcri-
grafton, slow, but exceedingly sure.
In the case of the garnet and topaz the
change is more rapid than i'm that of the
ruby and sapphire, but there is "a curious
difference in the result in topaz and gar
net, for while the latter grows lighter the
former appears to become cloudy and dull
in hue, losing much Of the brightness
characteristic of n newly cut gem.
For ages the opal has had the unenyiablc
reputation of being the most unlucky of
gems, and IL is believed that the jewelers.
themselves were originally responsible for
some of the superstitions and hard luck
stories connected with it, since To the pol
ishers and settlers il is one of the most
troublesome gems on their list.
Microtonists say that the prismatic col
ors and fire OF the opal are due to myriads
of minute cracks in the body of the stone,
the edges of which reflect the light at dis-
ferent angles and give the hues so much
admired. A stone full of cracks is liable
to split in two at any time, and disasters
of this kind. especially in the process OF
grinding and polishing, have occurred so
often that every gem polishing house has
its store of hard luck stories in connection
with the opal.
After the gem is set and sold the load is
taken off the mind of the manufactures
and transferred To that of the wcircr
Opals that have successfully passed the or
deals of grinding, polishing and setting do
not often crack afterward, but IL Is best
not to expose them to even the moderate
heat involved by the wcarer sitting in
front of an open fire. for the opal Is COM
posed principally of silicic acid, with from
To 10 per cent of water, a combination
which renders them very trcachcrous OBJ
jccts. The idea that they are otherwise un-
fortunate i'm the sense that they bring dis
aster to the wearcr may he dismissed as
supcrstitious.
OF all precious stones, however, the opal
Is the most open to be diseased. New
York Herald.