The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1894-10-28
MYSTERIES OF THE RUBY.
Extraordinary Peculiarities Present.
ed ii It's Structure.
Mineral Collector.

Mineral Collector.
In an address before the Royal Institution
in London Professor Judd said that all the
romance associated with famous jewels and
their history is Of Insignificant interest COM
pared with the fascinating actualities which
science has discovered in regard to the Won
derful gem f~amily-the aristocrats Of the
mineral kingdom. Eight years ago Eng
land was excited over the annexation Of
Burmah. and there were great expecta-
tions of what was to happen when the
British capitalist got his hands on the cele-
brated ruby mines of that kingdom Some
how or other these expectations nave not
been grati1ed.
The rubies are not forthcoming, but it is
not to be presumed from this that Burmah
has enjoyed a false reputation for those
remarkable stones Of price. Professor
Judd showed that while the ruby and it's
near relations are found in many parts Of
the globe. it Is in Burmah alone that the
gem is unearthed in its purest and most
fiery form. The intense pigeons blood"
color and peculiar fire % the Burmese
ruby give it extraordinary value as COM
pared with other red stones which come into
rivalry with 1t. for under the name of
"rubies' a great variety of gems not truly
entitled to the name have in ancient and
modern times passed muster.
The only substance which can truly be
called ruby is pure, limpid, fiery red
corundum. This mineral, corundum, is
crystallized oxide of aluminium, and forms
the basis of nearly every gem Except, of
course, the diamond) which we value for
hardness, b~rilliancy and color. A crystal
Of pure red corundum We call a ruby a
crystal of the blue variety is priced as a
sapphire" a green NfyStal we know as an
emerald" and other tints are known as
aQuamarine, topaz. and so on. Corundum
is found very widely distributed in the
East, especially in CeyiOn. ThiDet and Af-
ghanistan, and in the United States big
masses of impure blood-red corundum are
cut, and thus entitle the Americans to
claim the ruby as a native product. There
mese ruby, but with the exception of the
red diamond none is SO hard. They include
the red spinei, the rose topaz, red zircon,
In China than the ruby, and the various
garnets. This quality OF hardness is one
Of the most valuable features in the ruby,
for 1t enables the gem to take a high
polish. The diamond is. of course, harder,
and it is interesting to note that one of
tricaI furh ne1s'' cryst a f@ eomp pne eie Of
carbon and silicon-is only less hard than
the diamond itself.
The chief scientific interest Of the ruby
corundum flows from the extraordinary
peculiarities of structure that it presents
as we'll as from the mysterious qualities
found in crystals Of a great variety of
shapes, but all having a tendency to the
p tsiloEaap6 naeit a Of gf f%,nhin known ~ to te srys-
crystals Of corundum with polarized light
its structure is found to be wonderfully
terror face is covered with q strange net
work of sculpture. indicative of molecular
But probably the most interesting thing
about the corundum crystal is the fact that
it is nearly always found. to have inclosed
which lies imprisoned in ii. Stranger still
is the fact that these included foreign
bodies lie generally disposed of in planes
degrees, the result being to produce the
phenomenon of asterisn, which is the
term given to the white star of light which
is observable on certain Jewels cut with a
rounded surface. Very frequently the i'm
prisoned body is a minute bubble Of gas
or drop of liquid, containing sometimes
The microscopic cavities containing these
things are often very numerous. For a long
time the nature of the gas and fluid con-
tanned in the cavities remained a mystery.
The English philosopher Brewster was in
duced to investigate the subject by hear
ing that a ruby which an Edinburgh jeweler
had placed in his mouth. had exploded
while in that position, with unpleasant re-
has now been made certain that the nuid
is no other than liquid carbonic acid gas
reduced to that condition by being under
| great pressure.
The color of the ruby is another of it's
mysteries, and one which Prof. Judd was
only able to touch upon Slightly in his
lecture. The color is distributed most ir-
regularly and some corundum crystals show
in patches the tints of the ruby, the sap
phire. and the emerald all mixed up to-
gether. These colors are, of course. due to
the special way in which the structure of
, the crystal deals with the light passing
| through 1t, the ruby absorbing all the
rays except those which emerge to give IL
| it's characteristic color.
| How greatly these colors depend on mole
! cular and chemical changes going on in
way some gems behave under light and
heat. Professor Maskelyne mentions a dia-
mond which, when taken out of the warm
pocket and allowed to cool on the table,
turned a beautiful red. Professor Judd
startled his audience by declaring that
vatories at Kew gradually changed through
various shades of yellow to a distinct pur-
plish hue under the prolonged action of
light.
Rubies change their color in a curious
way under the action of heat. Blush ru-
bies turn perfectly green, and on cooling
regain their original tint. The blue sap
dunn crystal becomes green. Then there is
the strange property of "pleochroism' in
the ruby family and its kindred; they ex-
hibit different tints, according to the size
Of the crystal you are examining. Some
amorphous powdered oxide of aluminium
was placed In a vacuum tube and subjected
to the electrical discharge from a high-ten-
sion coil.
1t was shown that the white powder
glowed with the brilliant red of the ruby,
and that the glow continued after the dis
charge ceased-a fact which seems a GU
rious confirmation OF the ancient idea that
rubies would glow for a time In the dark.
a variety of corundum stones, artificial
rubies, etc, to show the greater or less