that,
in his time, carbuncles were made of glass so like the real that it was
only possible to know the difference by the hardness.
In
some ancient jewels, as in Eastern ornaments, rubies are seen very
roughly worked, but well polished and pierced from side to side, with
grave injury to the beauty of the gem.
In
the Hertz collection there was -a necklace composed of rubies and
rough emeralds of excellent quality and colour, and of the size of
small beans, pierced and strongly fastened together with a golden
thread.
I have never yet seen Oriental rubies engraved which could with certainty be called antique.
I have tried many times to have some engraved, but, in spite of the best efforts of skilled artificers, the results were but mediocre.
Wherefore,
Lessing, a scientific German, and the Count de Clarac, a French
archaeologian, having, as the result of their long experience, declared
as generally modern all the intagli on corundums which were asserted
by others to be antique, I adhere to their authoritative opinion with
regard to the Oriental ruby.
2. SPINEL RUBY.
The
spinel is an anhydrous aluminate, having a base of magnesia, zinc, and
iron, crystallized in regular octahedrons differently modified, and
sometimes in tetrahedrons.
In general, the planes of its crystal are more regular
