In order not to leave out any of the few things that I have mastered,
we will now discuss what is termed the reflector[46] of the diamond.
This reflector is put beneath such diamonds as are so delicate as not
to be able to stand a dark tint, such as would turn them black. If it
happen that their delicacy is not great, and their water is good, it
is customary to give them the tint under the step facets alone, and
to combine the reflector with this, and the result is admirable.
The reflector is made in this wise. You take a small piece of crystal
glass, quite clean, and free from cracks or flaws. You cut it into a
square of a size that shall fit into the bezel in which you propose
to set your diamond; and you tint your bezel with the black tint
of which we spoke above. Be careful to put the said reflector, the
glass of which is tinted on the lower side only, in the bottom of
the bezel, low enough to admit of the diamond standing over but
not touching it, because if it does it will not reflect well.[47]
This is how all the tenderest diamonds should be set, and beautiful
they look, too. Beryls and white topazes and white sapphires, white
amethysts, and citrine quartz,[48] are all set in the bezel with a
reflector of this kind, if they are of a sufficiently important size.
It must be borne in mind that no stones but diamonds will stand a
tint at the back, because they turn black, and lose their splendour.
So much for the reflector.
It is an extraordinary thing that the diamond, which is the most
limpid and brilliant of all earthly stones, gains a thousand-fold in
beauty when you, as it were, soil it with a black tint, while all
other light stones, as soon as you touch them with a tint, lose their
splendour, and turn black; forsooth this is owing to some occult
power, some secret of nature in the diamond, which human imagination
cannot penetrate. There are certain sapphires, which the ingenuity
of man can turn white, by putting them in a crucible in which gold is
to be melted,[49] and if not at the first heating, then at the second
or third. Indeed your cunning gem-setter will always pick the palest
sapphires, because, though they have the least colour, they are the
hardest in substance. The same holds good of topazes, which are of
similar hardness to sapphires, & so may be classified with them. I
propose here only to touch on these two stones in so far as they have
kindred qualities to the diamond. There are few, then, however great
their experience, when having before them the two stones could tell
which of the two was the diamond, often being unable to distinguish
them at first sight. The peculiar virtue of the diamond, however,
admits of the trying of a simple experiment, by which you can at once
distinguish one stone from another, and it is this. You take your
tint & rub both stones with it; your true diamond grows in brilliance
& beauty, the other becomes deadened and splendourless. And this test
suffices without trying the test of hardness too, but if you rubbed
the two stones together you would soon find out the diamond. Though
the sapphire is so much harder than the ruby & the emerald, it is a
thousand times less so than the diamond. By the way, I need hardly
mention that it would be absurd to test a polished gem by the above
method. That’s as much as I want to say about the diamond.
FOOTNOTES:
[46] _Specchietto._
[47] _This diagram may be taken to illustrate Cellini’s description_:
[Illustration: Diagram illustrating the _specchietto_ for the diamond
D. _Diamond._
A. _Reflector._
B. _Bezel tinted inside._]
[48] _Citrini._
[49] _Nel quale sia dell’oro che s’abbia a struggere._