I was watching the history channel not too long ago. I caught a show
that was about diamonds. They mentioned that moissanite was first
created by a Doctor Moissan who was actually trying to create the
first synthetic diamonds. Anybody know if this is true? I have not
used YAG in years but you know it was a lot more durable than CZ.
Doesn’t it have a bit of a yellow appearance or has it improved
since I last saw it? I agree with anyone who doesn’t understand the
fascination with moissanite. It is a very poor diamond simulant.
John Wade
Wade Designs
Doctor Moissan who was actually trying to create the first
synthetic diamonds. Anybody know if this is true?
I didn’t know till I looked it up. First, Dr. Henry Moissan was the
first to isolate fluorine, for which he won the Nobel prize. He also
essentially invented high-temperature chemistry using carbon arc.
Very famous chemist. The following is from “Gems Made By Man”, Kurt
Nassau. Note that the copyright is 1980, before gem moissanite.
Silicon carbide presents a special case, since it has shown so much
promise for so long. Known best under the mineral name moissanite
found in meteorites, or as the polycrystalline “carborundum”
abrasive, it has a hardness of 9 1/2, second only to that of diamond,
a refractive index near 2.7, and a dispersion about double that of
diamond. There are cubic as well as a variety of hexagonal forms,
with a birefringence of up to 0.043. It was first made by H. Moissan
and by E. G. Acheson in the 1890’s during attempts to grow diamond in
Moissan’s arc furnace. During the manufacture of silicon carbide for
abrasive use, some flat centimeter-size crystal plates have been
occasionally obtained. --It goes on to say that someday they might be
made colorless “Despite many decades of intense effort — it’s not
been possible to control either the color or even the crystal growth
itself----” Obviously, they solved that since 1980. By the way, for
those interested, it is formed by growth by reaction in the vapor
phase. "A silane compound containing both Si and C such as CH3SiCl3
may be decomposed in a hydrogen stream to form synthetic moissanite.
Hi John,
I do not know if Dr. Moissan was trying to make diamonds, but he is
credited with the discovery of microscopic Silicon Carbide crystals,
along with diamond micro-crystals in a piece of iron-nickel
meteorite from Canyon Diablo. The only type of meteorite which has
yielded Moissanite is the iron-nickel type. The newer YAG is very
colorless (one variety) and makes, IMO, a far better diamond
simulant than CZ, at least in larger sizes, as far as durability
goes. As I posted earlier, I have cut a number of replicas of
customers’ diamonds in colorless YAG and they were thrilled. I am
now working on a life-sized replica of the Taylor-Burton pear shaped
diamond for a customer who wants to present it to his wife as an
anniversary present, and it is being cut in colorless YAG.
YAG’s dispersion is lower than both CZ and diamond, but in larger
stones, with very crisp facet meets and superb polishing (and a
private trick), the difference it is not very apparent.
YAG is also available in a super-intense pure yellow (Cesium-doped,
I think), a couple variations of rosy pink, a couple greens (one is
a perfect Tsavorite match, and, hey, it’s got garnet structure to
boot…tricky to identify synthetic for the appraiser wanna-be’s).
But my favorite is the YAG that changes from saturated bluish-purple
in incandescent to beautiful royal blue in daylight, just like the
finest (and properly oriented and cut) Tanzanite. The bonus, again,
is that it is MUCH tougher and harder than Tanzanite and brighter,
as well. I sell a LOT of this in larger custom cuts to jewelers who
like strong markups and have the clientele.
Yep, synthetic Moissanite crystallizes in the Hexagonal sytem (in a
couple different classes, though) and it’s strong double refraction
drives me crazy to look at, although I will give credit to Charles &
Colvard for making sure it is usually cut with the C axis of the
crystal perpendicular to the table to minimize the effect if view
straight on to the table.
Wayne Emery
The Gemcutter
Natural moissanite is only found in meteorites and is very rare. The
company Charles & Colvard created moissanite in the lab and is the
only producer of moissanite – http://www.moissanite.com
Cathy Holleman
Crafty Cathy’s Creations
Winston-Salem, NC