diamondquestion...
Although there may occasionally be exceptional stones of all
the varieties you mentioned which would pose a challenge to
a jeweler examining them with the naked eye, the majority
will be identifiable as follows:
According to the diamond buyer's guide on this page from
Ray Ward Jewelers, both cubic zirconia and moissanite are
relatively easy to detect, since both of these are diamond
simulants, and not true diamonds:
"Whereas a synthetic diamond is an actual diamond created
in a laboratory, a simulant is a 'pretender,' another
'diamond-like' looking stone that is substituted for the
real thing."
CUBIC ZIRCONIA
"When it first became commercially available many years ago,
cubic zirconia (or "CZ") fooled quite a few people. It
doesn't anymore, and many can tell it's not a real diamond
at arm's length. Nonetheless, there are some good fakes out
there, and you need to be careful if dealing with a seller
you don't know well."
Still, in an answer by a colleague, kriswrite-ga, to a question
about distinguishing CZ from diamonds, she writes at length about
the difficulties of clearly distinguishing a CZ from a diamond,
referencing this webpage from Diamond Cutters Int'l:
http://www.diamondcuttersintl.com/diamond_education/articles/buying_diamonds/realthing.html
"How difficult it is to distinguish between a cubic zirconium
(a.k.a, C.Z.) and an authentic diamond depends largely on how
good the C.Z. is. Some C.Z.s are so authentic-looking that even
with a loop [sic] experienced jewelers can?t tell them from real,
high quality diamonds. This is why special diamond-detecting
devices are used at most jewelry stores today. Unless the C.Z.
is poor quality, it?s generally not possible to tell it?s not a
diamond with the naked eye."
Much more on the page, from the GA question:
http://answers.google.com/answers/threadview?id=308019
MOISSANITE
"Not all gem lab equipment is capable of detecting moissanite,
although C3, the manufacturer, is doing a brisk business
selling their $500 detector to pawn shops and jewelry merchants
who buy diamonds 'off the street.'"
"Moissanite is strongly doubly refractive, so it will pose no
serious identification challenge to a knowledgeable gemologist
(who can detect the 'facet doubling' by eye). But, undoubtedly,
it will fool many of the unwary for a while."
Much more on the page:
http://www.rayward.com/buyers_guide/diamonds.htm
The test used to discern moissanite is described on this page
from Diamonds-Gemstones-Jewelry.com, along with several other
tests:
"When testing for imitation or fake diamonds, the double-facet
test is used extensively to test for moissanite. If there are
doubled facets or a doubled reflection when you look at the
diamond through a magnifier, it is probably moissanite. Real
diamonds refract light in a single direction, so it's facets
appear as single lines."
"For best effect, tilt the stone and look at it from an angle
to see the doubling effect."
http://www.diamonds-gemstones-jewelry.com/diamond-imitations/diamond-double-facet-test.aspx
That leaves us Yehuda diamonds and Russian Brilliants as the
remaining contenders.
YEHUDA DIAMONDS
Here's a description of the process of creating a Yehuda Diamond
from the Pardise Jewelry website:
"Yehuda or 'clarity enhanced' Diamonds offer a fantastic looking
real Diamond for a low price. Of the Diamonds that come out of
the ground with feathers or fractures that reach the surface,
about one in ten will accept a special treatment called clarity
enhancement or fracture filling. It involves forcing in a
special filler material (a form of rare-earth glass first
developed by Zvi Yehuda) under very high heat and pressure.
The result is that the feathers are now almost invisible - like
dropping your contact lens in a swimming pool...it's there, but
you can't see it."
http://www.paradise-jewelry.com/yehuda_diamonds.htm
The means of detecting a Yehuda diamond is fairly simple, however,
and is provided on the Yehuda website:
"An enhanced diamond sold by Yehuda Diamond Company has a
built-in signature 'flash effect.' Easily seen under normal 10X
magnification, the flash effect appears as a line of vivid color
at the location of the enhancement."
"The flash is usually purple or green in color. When jewelers see
the flash, they can easily identify the precious stone as a
Yehuda Diamond and take the proper precautions of not introducing
the stone to the jeweler's torch or boiling acids or bases - the
only things that may effect the enhancement."
http://www.yehuda.com/flasheffect.asp
Since most jewelers wear a 'jeweler's loupe' around their neck,
which provides the necessary 10X magnification, the Yehuda Diamond
wouldn't prove much of a challenge to the average jeweler.
RUSSIAN BRILLIANTS
Lastly, from the Russian Brilliants site:
"Russian Brilliants® is a laboratory grown diamond simulant.
It was originally developed for use in the Russian satellite
space optics program. These cultivated gems are hand-cut and
come in different shapes and sizes. With their brilliance and
fire they possess many of the same characteristics and optical
properties of a natural diamond. They are very hard and will
cut glass!"
"Some jewelers have difficulty distinguishing between Russian
Brilliants® and a natural diamond. The eye appeal is equivalent
to the world's finest D-E color, flawless diamond. Beautifully
hand-cut, Russian Brilliants® is convincingly the closest clone
to a natural diamond. The appearance of Russian Brilliants® is
guaranteed to last forever."
Much more on the page:
http://www.russianbrilliants.net/introduction.html
As for detection, there are almost no results from jewelry sites
which discuss any means of detecting these stones, and the site
above is not very forthcoming. However another site which sells
these stones, called RussianStoneCompany.com, has more useful
information:
"Guaranteed for the life of the owner to never fade, change color
or loose its brilliance, fire or lustre [unlike cubic zirconium],
Russian Stones are hand cut and polished from Yttrium Zirconium
oxide(YZrO2). Simply the best natural diamond simulant available."
"In natural diamonds, molecules do not gather in ideal clusters.
This creates the black inclusions that you see when using a 10x
jewelers loupe. In contrast, Russian Stones have no visible
inclusions. Our components are purer. Our stones' molecules
gather in ideal clusters because they are grown in ideal
laboratory conditions."
"Each stone is then expertly cut and polished to an 'excellent'
finish. Visually Russian Stones possess many of the same
qualities that are similar to the world's finest D-E color,
flawless natural diamonds."
http://www.russianstonecompany.com/learnMore.html
This suggests that the way to identify these stones is more a
matter of noticing their *lack* of flaws than in identifying
their flaws. Real diamonds, other than the most perfect stones,
will have inclusions and imperfections which are less likely
to be found in Russian Brilliants.
Based only on the information above, Russian Brilliants *seem*
to be the only stone of the ones you mentioned that would not
be detected by a 'naked eye' inspection or a brief inspection
with the 10X magnification of a jeweler's loupe. However, they
might be suspected based on their lack of imperfections when
examined with a jeweler's loupe. Further testing would be
required, in this case.
However, on the site mentioned in Kriswrite's answer, there is
a column called 'Ask the Diamond Guy?', which makes it clear
that, in terms of buying a stone for yourself or a loved one,
the Russian Brilliants are:
"...simulants like c.z.'s, but with a P.R. [Public Relations/
Marketing] agent. I would go with a hand cut c.z. at $5-$50
a carat vs. $200+ a carat others are charging. A hand cut c.z.
is the best diamond simulant on the market in my opinion."
http://www.diamondcuttersintl.com/diamond_education/ask/view_item.asp?ID=13355
So, while the Russian Brilliant homepage compares their product
to machine-cut CZs:
"STANDARD CUBIC ZIRCONIA...Diamonique"
"At times man-made gems are more beautiful (rainbow affect) than
the natural diamonds they imitate. Standard CZ will take on a
pale grayish tone when exposed to sunlight over a period of time.
This does not happen with Russian Brilliants®. Unlike a naturally
formed diamond, almost all CZ components are purer and the
molecules gather in ideal conditions. Couple this with an
unsophisticated machine cut manufacturing process and you arrive
at the standard cubic zirconia or diamonique stone."
http://www.russianbrilliants.net/introduction.html
...Diamond Guy is saying that there are hand-cut CZs out there
which are considerably less expensive per carat:
"For my money the best simulant on the market is a hand cut
c.z. I don't like the color of moissanite and the cost of
the Russian brilliants. Imitation jewelry can look good many
years from now depending on a lot of things, like [how] rough
you are on it. I suggest you check out Ziamond.com and
czjewelry.com."
http://www.diamondcuttersintl.com/diamond_education/ask/view_item.asp?ID=11491
With regard to companies which seem to be implying that they
are selling synthetic, vs simulant diamonds, Diamond Guy says:
"At this point it is impossible to grow or replicate a real
natural diamond of any impressive size with a high clarity
or color grade. Yet if you surf the web there are over a
dozen companies claiming they are selling lab created
diamonds; synthetic diamonds. Pure fiction."
With regard to simulants in general, he says:
"A simulant is something that looks similar to a diamond but
does not have the same properties (weight, specific gravity,
refractive index, hardness, etc.). These would include c.z.s,
glass, white corundum, Y.A.G. (Yttrium Aluminum Garnet),
Graffs simulant, The Asha, Diamonelle and Zirconite to name
a few. Many of these companies (I won?t mention them by name,
you know who you are) make some pretty outrageous claims.
Some say they have created a super simulant that will sparkle
and last forever. Well, I guess that?s true but for it to be
true you cannot wear it."
Much more on the page:
http://www.diamondcuttersintl.com/diamond_education/articles/buying_diamonds/imposters.html
In conclusion, it would seem that Russian Brilliants are no
different than CZs, and telling these from real diamonds would
pose the greatest challenge to a jeweler, vs Yehuda diamonds
or moissanite, though the challenge would not be too great if
the CZ is poorly cut, discolored, or damaged, with rounded edges,
for example. A newer, high-quality, hand-cut CZ would prove a
greater challenge.
Please do not rate this answer until you are satisfied that
the answer cannot be improved upon by way of a dialog
established through the "Request for Clarification" process.
A user's guide on this topic is on skermit-ga's site, here:
http://www.christopherwu.net/google_answers/answer_guide.html#how_clarify
sublime1-ga
Additional information may be found from an exploration of
the links resulting from the Google searches outlined below.
Searches done, via Google:
yehuda diamonds
://www.google.com/search?q=yehuda+diamonds
"naked eye" zirconia moissanite yehuda
://www.google.com/search?q=%22naked+eye%22+zirconia+moissanite+yehuda
detecting "russian brilliants"
://www.google.com/search?q=detecting+%22russian+brilliants%22
identifying "russian brilliants"
://www.google.com/search?q=identifying+%22russian+brilliants%22
"russian brilliants" site:www.diamondcuttersintl.com
://www.google.com/search?q=%22russian+brilliants%22+site%3Awww.diamondcuttersintl.com |
