acausti and apiroti " cum ipsï non sentiant ignés," which properties perfectly suit the red corundum.
He,
according to the ancient custom, divides the masculine, which is bright
and resplendent, from the feminine, which is pale and less bright : " Fœminœ languidius refulgentes."
It
is said that preference is given to the Indian rubies, amongst which
those are retained as best which, from the extreme vivacity of red,
incline to amethystine violet : " optimiores .... quorum extremus ig-niculus in ametysti violam exeat." As these are the finest now seen, they are denominated amethyslizonti.
In the second rank as to value, they place the " sirtiti pinnato fulgoi-e radiantes," and give the name of lithyzonthi to the dark, pale, and discoloured Indian stones.
We conclude that it is most difficult to distinguish the different
kind of carbuncles when set, as it is still usual, at the present time,
to modify the tint, by placing under it a coloured substance, which can
impart brightÂness and beauty to a gem naturally pale and dull : " nee est aliud difficilius quam discernere hœc genera, tanta est in eis occasio artis subditis per quœ translucere cogantur."
As
in the case of other gems, the ancients used to make even false rubies
in red glass. King says, he saw one beautifully engraved with a head of
Medusa, so well imitated that he could not at first declare whether it
was gem or glass; even the flaws of an imperfect gem were imitated in
it ; and Pliny asserts
