Ruby, Oriental Ruby, or Red Sapphire.
This,
when of perfect colour and of fair size, is more valuable than any
other precious stone. If a diamond of 5 carats be worth £350, a
faultless ruby of the same weight would be worth quite £3,000. The
value of these gems above that weight increases iu proportion, and,
according to Mr. Streeter, a perfect ruby of 10 carats is almost
invaluable. He says that a perfect stone of 5 carats will fetch ten
times as much as a diamond of the same weight. The number of fine large
rubies of undoubted genuineness is small, though there are on record
several gems of immense size reputed to be rubies. Nearly all the great
historic rubies now extant have been pronounced spiuels, and Mr.
Emanuel states that the two large stones shown amongst the jewels of
her Majesty at the London Exhibition of 1862 as rubies, are simply
spinels.
The
difference between these two gems is easy of determination, and there
should be no uncertainty about the matter, although the colour of
spinel often approaches that of the ruby, yet the property of dichroism
that the ruby has is wanting in the spinel, and at once distinguishes
it from that mineral. Those gems crystallizing in the cubical system,
when viewed through the dichroiscope, do not exhibit the property of
dichroism, and the spinel crystallizes in this system; while the ruby,
which crystallizes in the hexagonal system, when tested with this
instrument invariably gives the two squares of different hues, or shows
dichroism. This test also distinguishes the ruby from the garnet, as
the latter is also cubical. Besides this test of dichroism, spinel may
be distinguished from the ruby by its deficient hardness (corundum
scratching it), and by the lower specific gravity of spinel. The
specific gravity of the garnet does not differ much in some instances
from that of the ruby, but it is much inferior in hardness, and it is
fusible in the blowpipe flame, ruby being infusible.
All
the fine rubies are supposed to have come from Burmah ; at any rate,
two authenticated, gems from that country reached Europe in 1875. When
recut they weighed 32-5/16 and 39-9/16 carats respectively, the
larger one being-sold for £20,000. The necessities of the Burmese
Government were the cause of their transference to Europe.
The
ruby mines of Burmah being a Royal monopoly, all persons finding rubies
over a certain weight were bound, under penalty of death, to deliver
them to the Government. It is very probable that many stones of large
size have been reduced to smaller portions to prevent their being
handed over, thus causing loss to the country and the Government.
There appears to be
little doubt that the Boyal Treasury of Burmah contains some large and
beautiful rubies; these most probably will find their way eventually to
the European market.
Rubies
are also obtained from Ceylon, the Chinese provinces bordering upon the
Burmese Empire, from Tartary, Siam, and in smaller quantities from
several other localities.
The
rubies that are now being obtained in large quantities in Siam, are
considered to be of an inferior colour to those from Burmah, but the
author was assured by a gentleman connected with the Siam mines, that
this difficulty of colour is got over by transferring them first to
Burmah, and then forwarding them to Europe as stones from the latter
country.
It
is a well known fact that when the diamond was first obtained from
Brazil in large quantities, a similar prejudice arose against these
gems, but the difficulty was got over in that instance by first
shipping them to India, and then to Europe as Indian diamonds.
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