"David Harmon" wrote in message
m...
On Wed, 19 Nov 2008 15:41:32 -0500 in rec.crafts.metalworking, "Ed
Huntress" wrote,
"Larry Jaques" wrote in message
. ..
And Cubic Zirconia is the trade name of one manmade diamond.

Uh, not that I know of. It's the name of an *artificial* diamond. It isn't
diamond, manmade or otherwise. It isn't even carbon.

"Artificial" is pretty much just another word for "man-made".
I would call it imitation diamond or diamond substitute.

Man-made diamond, like GE's crystalline diamond used for diamond compact
tools, and the vapor-deposited synthetic diamond used for coating tools, is
real diamond. Chemically, it's indistinguishable from natural diamond. It's
carbon, and it's just as hard as natural diamond.

Cubic zirconia and other artificial diamonds are not diamonds at all.
They're completely different compounds, and they're somewhat softer than
diamond. Zirconia, for example, is zirconium dioxide.

Now that man-made, or synthetic diamonds are so common, it's good to
distinguish them from the artificial stones that only *look* like diamonds.
The synthetics, again, are real diamonds. They can even make some
gem-quality synthetic diamonds today.

--
Ed Huntress