The
spinel ruby and the balas ruby must be carefully distinguished from
this valuable gem, as neither in nature nor composition do they
resemble the oriental ruby.
"The
oriental ruby," says Babinet, "ranks first for price and beauty among
all coloured stones. When its colour is of good quality it has the
vivid tint of arterial blood (a tint called 'pigeon's blood' in
commerce), or of the very centre of the red ray in the solar spectrum.
It is the perfect red of the painter's palette, without any mixture of
violet or of orange. Several of the reds in the stained glass of our
ancient cathedrals, when the daylight pours through them, give an idea
of this brilliant colour.
"
The ruby is extremely hard; and after the sapphire, which surpasses it
a little in this respect, it is the hardest of precious stones, always
excepting the diamond, to which nothing can compare. M. Charles
Achard, the highest authority in France in all that concerns the
traffic in coloured stones, remarks that weight has not the same effect
in their case as in that of the diamond. Every diamond, from the very
smallest specimen upwards, has its value like gold or silver, according
to weight; but in the case of rubies and other gems the little
specimens have hardly any value; and these stones only begin to be
appreciated at the moment when
