There is no way of knowing how much amethyst is of synthetic origin.
It can be detected only with very costly procedures thereby making
it uneconomic.
Pardon me for butting in on this thread, especially since I haven’t
been following it particularly well, but I seem to remember reading
an article in JCK magazine recently about a phenomenon called
“twinning” in synthetic amethyst. I believe this is visible as a
sort of cross grain pattern under polarized light. Perhaps one of
our more informed gemologists could add to this.
There is no way of knowing how much amethyst is of synthetic
origin. It can be detected only with very costly procedures
thereby making it uneconomic."
I must say this is statement could not be any further from the truth
if it was written on the MOON. There are many ways to tell the
different from the Man-Made Amethyst from the stuff that comes out
of the Earth and they do not cost a lot of money. With a little time
and a loupe you can tell the different by studying the two. Their
are many methods and the easiest way to find them out is to go to a
site like http://www.gia.org
http://www.yourgemologist.com or a faceters digest. I can go on but
my word to say they are uneconomic is really a scapegoat. I guess
there could be a gem dealer, cutter or jeweler that cannot afford a
loupe, some books and a little time to study. There are some real
easy test that are quite costly to test just one stone because they
are setup for large scale testing but a simple GEM TES UV LIGHT can
tell you MANY things about how the rough the gem came from was form.
ONE last thing. You can call the GIA and do an online search of the
Magazine Gems and Gemology and ask them to send you the issue that
tells you all about how to ID the Man-Made Amethyst and you should
get the issue one the Amatrine also.
I hope I have pointed you to where you can find the answers. Please
check this topic out further because it may just help save you a big
legal battle in the future if some sends a gem they got from you to
a GEM TRADE LAB and it comes back Man-Made and that is not what you
sold it do them as.
I seem to remember reading an article in JCK magazine recently
about a phenomenon called "twinning" in synthetic amethyst. I
believe this is visible as a sort of cross grain pattern under
polarized light. Perhaps one of our more informed gemologists
could add to this.
Lab-grown quartzes including amethyst are grown in hydrothermal
solutions. They require a “seed crystal” to begin the process. Early
types of hydrothermal amethyst used seed crystals with no Brazil law
twinning which is almost universal in natural amethyst. Depositions
onto the seed crystal showed the same lack of twinning. Since
twinning can be fairly easily detected in polarized light as
interference colors when the stone is viewed along an optic axis,
this test is used to distinguish between natural and older
synthetics.
Now the game has become much more sophisticated with new material.
Twinned “seeds” are used, eliminating simple diagnosis. Some skilled
gemologists can detect “breadcrumb” inclusions in the new synthetics
but they are difficult to find – if they are present. The best
guarantee of natural amethyst is the presence of natural inclusions,
slight color-zoning and color variation between stones. Buyers should
be skeptical when dealers display dozens of ultra-clean stones with
identical color saturation and appearance. Unfortunately,
distinguishing between fine flawless natural amethysts and synthetics
is now a job for the big laboratories.
William, I went to the gemologist site and he said exactly what Ron
Mills had said. Synthetic amethyst is so good that even GIA is having
a difficult time separating synthetic from natural. Does anyone have
an article written by one of the major labs in the last 5 years
giving up to date synthetic quartz detection techniques? I would
like to know. Please respond to me off list if you are a lurker.
My own experience is that in the last 10 years the lab grown
material emulates the natural so closely that if the stone does not
have distinctive zoning, twining, and inclusions I can not tell the
difference. I have used 10X, immersion, and microscope. I do not
know if all synthetic quartz will fluoresce. Is fluorescence a
reliable test? My intuition says it is not or everyone would know it
was a definitive test. Anyone have any experience with this test?