This
one would be about four carats; this a little farther on would come to
about two and a half. There are a hundred and forty-two carats to an
ounce; it's a very ancient unit of weight." I imitated him and picked
up a diamond here and there and put it down again, trying to look
insouciant. Moving on, he continued talking: "Here are spotted ones,
what we call piqued; as you probably know, they've got to be cut
carefully so the spots won't be included, and that lowers their value.
These, less than a carat, are called melee; small, as you see, but
fairly regular. Anything less than a carat that's broken, though, is
considered a chip. It hasn't much value. Broken stones that weigh more
than a carat are known as cleavages."
We
stepped back and surveyed the length of the table, and he showed me how
the different colors of the grades were plainly visible—blue, white,
and various shades of yellow from pale to amber. Near the end of the
room was a pile of brownish stones. They were marginal, he said.
Anything of lighter color would be categorized as "fancy," worth
whatever price it might fetch from a man whose taste was for fancies,
but a stone of deeper color would be merely industrial, selling for
much less than gem price.
"Diamond
values are tricky things," he said. "A shade of color makes all the
difference; it's what you might call dramatic. Fashions in colors come
and go. There's a great demand at the moment for a rare greenish shade.
We're doing some work on color in the research laboratories just now;
it's never been discovered to a certainty what makes it. It's hard to
generalize, but certain colors in stones do seem to occur in special
parts of the mines, associated with certain other minerals. That
Flickr
Stumbleupon
Scribd
