Gemstone Fraud

What are some different gemstone frauds that exist? What are some unique gemstone frauds that most people overlook?

Please feel free to comment any gemstone frauds that exist, from Pakistan and India, to the United States and the UK. I would like to read all of your messages. Thank you!

Are you talking about fraud where folks promise stones and then don’t send them or suchlike? Or are you talking about stone switching of jewelers and repairmen or are you talking about passing off a cheap stone, synthetic or natural, for a more expensive one? -royjohn


royjohn, all of those. I would like to hear from you any of those frauds that you would like to message about. Thank you!

Hello Thomas,
If I had the time to answer this question completely, I think it would end up being a chapter in a gemology book, or maybe a whole book. I did search on this forum for “fraud” and “fake” and that brought up some posts with some other search words you could use to find more. There were also some entries with stone switching in them. Jewelers have some strategies for avoiding the charge of stone switching, including photographing, weighing and describing at take in without saying “5 ct natural sapphire, very clean.” You say “5.03 ct blue stone described by the customer as a blue sapphire and untested at take in.”
As far as synthetics and imitation gems are concerned, there are whole chapters in the gemology books on those topics, and I refer you to those. Because synthetics have more or less the same physical and chemical properties as their natural counterparts, differentiation usually focuses on using the loupe or microscope to look at inclusions, striae, etc. In some cases, and you have to know which, you need to send the stone out to a lab, because if there aren’t inclusions that clearly indicate natural or clearly indicate synthetic, you need to fall back on the sophisticated instruments which are generally only present in the big labs…Raman spectroscopy, etc. There are some fairly good libraries of inclusion photos available on the Internet now which you can use instead of buying $500+ worth of books by Gubelin and Koivula…with approximately as good reliability, altho’ the G & K books are great references and full of incredible photos. The exact URL’s for these sites I don’t have in front of me…one is a site in French, but I seem to have lost the URL…maybe someone else can help. Beyond this, you’d have to PM me for more and we could discuss you employing me as your research assistant (LOL!), because an exhaustive treatment of this subject would take hours and hours. Hope this helps! -royjohn


I almost forgot that there are some synthetics that have different responses to certain filters (that’s what the Chelsea filter was developed for), and some synthetics have different responses to UV light than their natural counterparts. Maybe some differences in magnetic responses (see, Kirk Feral’s great site). Differences in UV transparency can be used with a special light box and that’s described in Peter Read’s book on gemology, but it has limited utility for one or two gem species, if I remember right. That’s all I can think of for synthetic vs natural tests at the moment. Check the books…you do have those, don’t you? HTH! -royjohn

1 Like

I don’t have any books on gemmology. I solely rely on information on the internet. But there are plenty of resources on the internet.

Thank you, royjohn for your answer! I will study what you said!

I agree with everything Royjohn said, but he knows more than I do about gems in the rough. I will have to check out some of the books he mentioned. My favorite reference is Gemstones of the World by Walter Schumann and another one I refer to is Rocks, Crystals, Minerals edited by Rosie Hankin. I buy Gemstones that are already made into beads and temporarily strung, mostly round, but some facetted and carved beads also. The primary fakes, imitations and synthetics I have run into include: Dyed Magnesite and Dyed Howlite sold as Turquoise and Lapis Lazuli. Light and spotted Lapis Lazuli dyed to look like higher quality Lapis Lazuli. One bead vendor actually told me they don’t list them as dyed “because they only dye the white part”. Really? Serpentine sold as “BC Jade” which is Nephrite, much harder and more valuable than Serpentine. Dyed Quartz in a variety of colors sold as “Malay Jade”, and lab created Citrine. I must say, that although it is not as valuable, I like South American Amethyst for its clarity. Zambian Amethyst is so dark, it sometimes looks almost black, and I suspect some of it is probably Dyed Quartz, which unless the dye comes off, is hard to test because Amethyst is a Quartz.

1 Like

Interesting, lottied. Thank you for your answer! I do have turquoise and lapis lazuli jewellery, but I paid much money for the lapis lazuli, but not as much for the turquoise. The turquoise chip beads I have are probably fake.

I had a certified gemologist at a fine jewelry store examine some of my earlier purchases. He showed me how to test them and how to detect if they were dyed. Real Turquoise is getting pretty scarce. The Hubai mines in China are scraped to the bottom and most of the good quality in Arizona is gone, too. Since the US doesn’t trade with Iran, that source is unavailable to us also. Other sources are not good quality, more brown than blue or green. People who have Turquoise stashed from 20 or more years ago can command a high price for it now. Natural Lapis Lazuli with good color is very expensive. Since Afghanistan is the only source of good quality Lapis, the war there and now the Taliban in power, there are a lot of dyed lower quality Lapis and out right fakes on the market now.

1 Like

This is nice to know. Thank you!

Perhaps the biggest scam in transparent stones is zircon aka natural zirconium silicate. The fraudulent cubic zirconia aka zirconium oxide (CZ) is openly marketed as natural zircon by vendors who have no integrity and probably know little chemistry. This is not to denigrate a synthetic and very birefringent stone that clearly pleases many who want bling without hefty dollar cost. However, zircon itself has an ancient history which saw it being used to illegally supplant diamond. Interestingly, high quality zircon is rarer than diamond but suffers from heat treatments that seek to upgrade it from its natural color. Blue zircon results from reductive heat treatment of certain brown stones. Yellow stones are usually an unwanted reject from such treatment. Such treatment can also give colorless stones which also occur in nature. Practically all cheap “natural zircon” is synthetic CZ. For example, most “zircon” beads are CZ and their uniform color is a dead give-away as natural zircons are hard to match. A polariscope will easily distinguish CZ which is anisotropic from tetragonal real zircon. Also, CZ will not change color on heating above 900 Celsius, but don’t try on your beloved’s ring!


This is very nice to know! Perhaps there’a reason why I don’t have any Zircon gemstones… so many of them on the market may be fakes! Fortunately, I’m just not interested in zircon, so it’s unlikely I will fall into that fraud!

Thank you for your answer! It’s good to know, so I can look out when anyone I know want’s to buy Zircon, to keep the price in mind, and what seller one buys it from.

Where do Zircon’s sell as cubic Zirconia the most? What country does this fraud happen in the most?

All Countries

Yes. I would like to hear a more specific answer on the various gemstone frauds that one can find, and where these gemstone frauds are most common. Thank you.

Sorry, I meant that all Countries are guilty of using the word Zircon instead of Cubic Zirconia.


Oh! Well, it’s good I’m not interested in genuine Zircon gemstones; I can avoid the trouble. I can tell anyone I know who wants a genuine Zircon gemstone to watch out. Thank you!

I agree royjohn is always helpful and replies.

Everyone that leaves an answer for me I find very helpful. I thank all of you!

I find, too, there is “a thousand ways to fall” in regards to scams and shades of dishonesty and in the gemstone trade…

Without own proper knowledge, I sent out reputable high-end dealers in Asia to certification labs, only for them to come back looking down into the floor.
Speaking of; I see some certificates stating for example “Natural ruby” blahblahblah, and a small remark GF somewhere… now, of course we know what that means, but if you didnt you would belive it was much more valuable than it is.

I often see reputable jewelers without proper knowledge, charging top dollar for stones that is at best crap - even though they source from Switzerland etc… Of course, its not intentional, its just because they lack knowledge in gemology.

My passion for gemstones have made me decide to study this amazing world of gemology and faceting arts for a minimum of 5-10years (probably for the rest of my life)… But im early retired at 40+ with background in tech&mech R&D, as well as product design, so im probably far more interested in the technical aspects to my gemstone collection than most would be.

I wont buy faceted stones anymore without bringing my suitcase of equipment first, but i still buy unchecked rough occasionally online etc.
If its not what expected, it goes to the box “synthetics”, “heat treated” or whatever it falls under.
If its full of inclusions, more that the pictures or statements, its a true treasure chest for my study and future microscope photography hobby, and will be stored in a box with location/source data as precise as possible…

Now, I have no intention or reason to sell/resell gemstones - so it doesn’t matter much with the “scams” i have encountered buying gemstone… the lessons are more valuable than the loss for me in that regard. Painful lessons can be valuable!
The ancient Roman philosopher Seneca two thousand years ago stated:
“A gem cannot be polished without friction, nor a man perfected without trials.”

Oh well, that was off-topic!

Im just beginning myself, but for everything new I learn, I realize I know so little.
IGS is a truly amazing place to start learning. I think never in my life i`ve seen so much available direct knowledge to such a low cost… Anyway, lets not make my gratitude make me emotional.

My only one take-home here is this:
If you are serious about collecting gemstones, spend significant amount of time everyday to learn as much as you can of gemology, faceting, the trade&market and everything around it. When your knowledge is huge, experience is big, and toolbox is respectable, I think you don`t have too worry too much about scams in obvious forms. If anyone can trick you then, the lesson will be a valuable gem in itself.

If not becoming a life-long student to ones passion, maybe its better doing something else?

1 Like

What do you mean by this? Looking down on the floor… stones that are crap? What do you mean by these statements? Can you be more specific?