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Learning how to identify simulated gems from real gems.

Hello I would like to be able to look at a stone and be able to tell if the stone is real. With online buying, I have found lots of the gems are simulated gems. Just want to make sure I get full value of what I am buying, Any tips would be appreciated.

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Take a gemstone course at GIA?

Hi looking at gems online and or in the hand is not possible to tell if it is natural, synthetic or a simulant
you always have to test a gem to ensure if it is natural and what the seller has stated it is. it has been said many times on this forum if it is too cheap it probably is not what you think you are purchasing.
I learnt a long time ago that no one can just look at a gemstone and know what it is, after 30 years of buying fossicking and looking at nearly every gem you want to name I thought I could just look at a gem and call it out. How surprised I was when I did my gemmology diploma to find out that I was not as good as I thought I was in identifying gems by just looking at them.


Depending on the gem species, it can still be difficult at times to determine natural vs. lab grown even with a gemology degree. Some inclusions from lab grown material can look like natural. Best to have a cert on something from a good lab, especially if the item has a high value. Buying from a reputable dealer goes a long way, especially with a good return policy. We have a 10 day return policy for any reason, BUT our Life Time Guarantee indicates that if the item is as not described as on the invoice (such as Natural or Unheated, etc.) it can be returned anytime - so finding out something is say lab grown and not natural, would fall into that category… Some of our unique or more costly gems have certs from GIA and that was done for re-assurance for customers; we also cert at times to verify that a Corundum (Sapphire or Ruby) is Unheated if sold as Unheated to us during our international gem buying trips abroad. (There have been times that we were told something was Heated and it turned out to be Unheated - which is always a pleasant surprise!). Hope this helps.

L. Allen Brown
Gemologist (GIA - 1991)
All That Glitters


Maybe this is a matter of semantics, but “testing” really isn’t the way to ID most synthetics unless by testing you mean magnification to look at inclusions. Yes, some inclusions in synthetic do look similar to those in natural gems, but careful study and a library of photos of inclusions in natural vs synthetic will allow you to distinguish most stones without resort to GIA. It comes down to having enough experience. You might also want to get some samples of synthetic gems with characteristic inclusions, altho’ having one of every luxury synthetic would cost some money…-royjohn

Here is one site with lots of inclusion photos…it is not particularly easy to navigate to what you want, but many pics of inclusions in synthetics are there:
There are other similar sites…I can’t find a ery good French site right now…-royjohn

Hi RoyJohn thank you for your email, I fully understand that you would normally need a microscope to study any inclusions to ascertain if it is natural or synthetic, I have many books with diagrams/photos of inclusions in regard to natural and synthetic gems. I try to keep it relatively simple most of the time on the forum as we have members with all the experience in the world and others excuse the expression that have no idea
once again thanks for your email

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Hi SydP,
Thanks for responding…I understand what you’re saying and pardon me if I’m parsing too closely…but, LOL…you can actually identify many gems by sight…if that’s under magnification and if you have the right knowledge…I, too, find it interesting (!) that some folks think we can look at a picture and ID a gem. -royjohn

First, understand the glossary:(1) Real (natural) gem- one that comes out of the ground.(2) Man made(Lab Created) made in a lab, but has the same properties (S.G., R.I. etc.) of a natural gem.(3) Simulated- FAKE! Does not have the properties of a real or lab created gem.

It is a learning process. For a small expenditure ($200) you can get a refractometer and specific gravity equipment. Check out Youtube videos on how to use them. This will nail down about 90% of your need.

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