I am just gearing up for my GIA Coloured Stones exam so Iâve got that info right here⌠Without quoting my course materials verbatim, hereâs the gist: Quartz was first commercially synthesized in the 1950s. In the 1970s synthetic amethyst using the hydrothermal method entered the market (grown on untwinned seed crystal). Prices plunged because consumer confidence was shaken. At that point standard gemological equipment could be used to detect synthetics. But, in the 1990s producers began using twinned natural seed crystals, which makes it extremely difficult to separate natural from synthetic. Advanced gemological testing would be required.
Itâs also mentioned that much of the jewellery industry ignores the issue of synthetic amethyst detection and disclosure (as reported by trade publications) and theorise that itâs because of the expense of testing and that the prices of both materials are fairly low.
Wendy is correct â the price of synthetic quartz vs. natural quartz is pretty much the same. Since both materials are very common in the gem market with almost no one willing to pay a premium for advance testing, there is no financial incentive to figure out which is which.
The only way I am confident I have natural quartz is if I cut it myself from the rough. In the rough, it is not difficult to tell natural from synthetic when there is crystal structure evident. (Though, I suppose, synthetic could be made to look like natural, but given the prices there is no point for tricksters in doing this).
Whoever purchases the finished stone must rely on the cutterâs honesty. Like so many other parts of our industry, it again comes down to trust.
Is there a resource which gives the inclusions found in natural and synthetic amethyst to compare them?
If I am buying cut stones to recut, then to have a way to determine synthetics, even if not guaranteed, would be useful. I would prefer to only deal in natural materials as much as possible and I will be selling cut gems via ebay until I build up a reputation. The following image is an amethyst I have finished cutting as an example.
First off: âWendy is correct â the price of synthetic quartz vs. natural quartz is pretty much the same. Since both materials are very common in the gem market with almost no one willing to pay a premium for advance testing, there is no financial incentive to figure out which is which.â
NO: Synthetic amethyst is MAXIMUM $1ct (if you want 20000cts, you can get it as cheap as $0.30ct, probably less). Fine quality Uruguayan amethyst starts at about $15-$20 USD/ct, and that is for parcels, dealers in NYC are selling the best qualities for $40-$50ct for single gems.
Amethyst prices have been rising (like all gems), a friend said to me about a decade ago: âWe are going to find out how much synthetic amethyst is around when it gets expensive enough for people to start getting certs on itâ Well, we are getting there already (disclosure, this is my site): Certified Gemstones | Skyjems
Now, onto detecting natural from synthetic⌠Almost all natural amethyst has at least SOME zoning to it.
SOME synthetics do, but, the zoning is perfectly straight and obviously not natural. Also, no banding of color.
So⌠the quick and dirty way to check is put it in a white bowl with water in it, table down. If there is no zoning, you have a âmore testing requiredâ situation. If there is âflowingâ zoning through the gem, you are almost certainly good.
Nice cut job. The only wat to know for sure is to get your stones from the natural rock its self. I have a nice size one laying around here some place that I would love to have a stone cut out of some day but I am not sure of the quality of the colors. You would be welcome to it if you could find a nice stone to cut out of it for me. It has quite a few thousand carats in it. I will send a picture of it to you as soon as I locate it. I have it packed away right now.
All the best.
Otter.
Otter, I donât have the facilities for a stone of that size. You would need a trim saw, possibly a slabbing saw depending how large the piece was, and probably 8 inch laps minimum.
I am happy doing smaller 1-10ct stones and selling them via ebay for now. Just need to build up a reputation.
The idea that prices of synthetics and natural amethysts are the same, is one that should not continue to be taught.
With enough experience a polariscope will more than often give you enough evidence of its natural vs synthetic origin. As a laboratory, we can attest that, while the concept of experimentation of twinned synthetic growth is possible; it has not been a practical method of growth. We have as yet to come across a twinned synthetic amethyst after having tested hundreds of amethyst. BTW, we will also use FTIR (infrared spectroscopy) to backup our tests.
Hi Cameron gems. Amethyst synthetics are heavier than natural stone. Color wd be so even. Check my Instagram for my latest batch of amethyst if: derbrilliant