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Pair of black diamonds

I have a call for a pair of black diamond stud earrings. Total weight
one carat (1/2 carat each) round brilliant OR princess cut.

With all of my resources in diamonds, I have never dealt with black
diamond (nor am I usually interested in doing so,) but this call is
for a good friend.

Any orchidans able to fill this order or point me to a good source?

Lord of the Rings
607 S Hill St Ste 850
Los Angeles, CA 90014-1718


Black diamonds are becoming so common, even Stuller sells them.

They list a 1/2 ct size in their catalog.


Douglas Zaruba
33 N. Market St.
Frederick, MD 21701
301 695-1107

The problem faced now though is: Are these naturally black or
treated? Not so easy to separate!

I BELIEVE that they’re ALL treated. Is that incorrect???

David Barzilay
Lord of the Rings
607 S Hill St Ste 850
Los Angeles, CA 90014-1718


At one time I saw some diamond crystals that were so full of black
inclusons they appeared black until you studied them closely and saw
the density of the inclusions. I have never seen one of these stone
cut as they were considered specimens or waiting to be crushed into
diamond abrassives. As a specimen it was quite attactive.

Gerry Galarneau

I BELIEVE that they're ALL treated. Is that incorrect???

That is a safe assumption, yes. Most of the material that comes out
of the ground a black color (called Carbonado) is an aggregate, and
isn’t cuttable (as an aggregate, there are no cleavage, sawing or
ploshing planes). Typically, diamonds that are brown, yellow and
somewhat black, and are too heavily included to cut a decent-looking
or durable stone, are irradiated to make them as black as possible.
They are then tested for radioactive levels. Any irradiated stones
with unsafe levels are stored until their half-life expires to safe
levels. If I ever shop for them at shows, I know a guy with a geiger
counter (and I’m not kidding - I’d borrow it to be sure!).

I just read that the West Australia state government has agreed to
help Rio Tinto with the half-Billion-dollar price tag of
redeveloping the Argyle mine for underground mining, pending
inspection by an independent auditor to determine whether Rio Tinto
actually needs the money. The Argyle mine, while producing the few
ultra-expensive pink/purple/red diamonds, is as well known for their
usually small yellow (champagne) and brown (cognac) stones, as well
as the small black ones we’ve been talking about. Perhaps prices
will drop in a few years if and when they go underground.

James in SoFl

 I BELIEVE that they're ALL treated. Is that incorrect??? 

Actually, for the most part you are correct. Most of the black
diamonds on the market now are currently treated. There are still
some which are natural. A few years ago I had a 3ct black diamond
which was natural. It had small black platelets all running in the
same direction throughout the stone. If you turned the stone just
right you could see through the stone. Any other direction and the
stone was actually semi-translucent, facing up black, not gray.
Quite a unique stone. Others have so many black inclusions throughout
that they also face up black. They should have been made into saw
blades or finger nail files but someone faceted them.

Most if not all you will see on the market now are treated and
totally black. Interesting for many creative designs.

Rio does carry some smaller sizes and I am sure we can get most
anything you may need. Not the usual disclaimer, I work at Rio. Call
the diamond department and ask if you don’t see what you want.


Phillip Scott G.G.
Technical Support & Sales
Rio Grande