According
to Cardan, precious stones are engendered ("in the same manner as the
infant from the maternal blood") by juices that distil from precious
minerals in the cavities of the rocks: the diamond, the emerald, and
the opal from gold; the sapphire from silver; and the carbuncle, the
amethyst, and the garnet from iron.
In
enumerating the flaws or imperfections which may be presented by
precious stones, he makes a remarkable reflection, and one which has
been considered an ingenious plea for excusing certain well-known
imperfections of his own.
"In
precious stones,"he says, " imperfections are in reality less common
than in animals and vegetables; but they are more conspicuous in
jewels, simply because their nature is more brilliant and more rare.
For the same reason, great men appear to have more vices than common
mortals; but this is a delusion and an error. The lustre of their fame
and the splendour of their names render their faults only the more
apparent; while the ignorant vulgar, under favour of their obscurity,
escape having their vices noticed."
It was admitted without question, in the time of Cardan, that precious stones were living beings.
" And not only do precious stones live, but they suffer illness, old age, and death."
He then speaks of the different virtues possessed
