Hi. I was wondering how one can tell the difference between a read diamond and a fake? What are the characteristics one should notice in a real diamond compared to a fake diamond or CZ? For example, with one of my rings, the diamond glows brightly under a black light. When I compared my rings "glowing" to another girl's ring, her diamond barely glowed. What is the explaination for this and is my diamond real?

Since the subject matter of this thread was "Fake or Real" and the initial poster asked how to determine "fake from real" diamonds here is a simply little test anyone can perform to help determine if what they are looking at is a real diamond or a CZ.

Step 1.

Take a blank piece of paper and make a dot on it with a pen.

Step 2.

Take the stone in question and turn it upside down on the paper. We will be positioning the diamond, table down and centered on the dot.

When you center the gemstone on the dot ...

In a CZ you will see a circular reflection of that dot clearly through the pavilion. The stone on the left is the CZ. The stone on the right is a real diaimond.

A diamond will break up that reflection to the point where it is almost imperceptible. In a CZ it will be very easy to see.

There are other ways of making the distinctions between fakes and real but this is an easy simple test that any laymen can perform.

Peace,

Now THAT is a heck of an easy test. Thanks, Rhino, for sharing that wonderful tidbit. I learn so much every time I visit this forum!

Curious if there is a similarly easy test that can be applied to a mounted stone?

I usually recommend the pocket conductivity tester that most jewelers seem to have. It's fairly accurate, and costs nothing.

Oh I love that test! I want to try it on something now! But I don't have any CZ stones. Time to go shopping!!!!

Getting back the fluorescence issue just because, I once went into a jewelery store where the designer puroosely sought out diamonds with varying amounts of fluorescence and created the most beautiful pieces using the fluorescene as the design. The colorations were incredibly subtle but strong enough to notice. I couldn't stop looking at them. What an eye this guy had.

Princess Tess

typically determining whether a mounted diamond is real or not is much harder than a losse one...but there are a few things you can certainyl do to help 'ease your mind' - though they are NOT exhaustively accurate like rhinos paper test....

1) scratching/scuffing. As we all know diamonds are really quite hard! CZ really isnt..... if you're looking at a ring and can get a loupe or magnifiying glass, have a good look at the facets of the stone (tilt it so that the reflection is compeltely on the surface). CZs of any age will almost definietly show light scratching and scuffing - diamonds are very unlikely to.

2) 'sharp edges' - its possible to cut a diamond much more 'finely' than a CZ - so the edges between the facets will always be very sharp on a diamond. Obviously experience is rather helpful here cos otherwise you dont know what you should be comparing to, but if you have a chnce to look at both together you can clearly see differences

the other tests tend to require toys - like heat and electrical conductivity......

Oh, and another great test for an unmounted CZ/diamond is weight. same size CZ will be nearly twice the weight of a diamond. having the expected weight of say .25, .5, .75 and 1 ct in your head makes that a nice easy thing to work out!

cheers
Night

Excellent input nightmare. Here are some graphics that demonstrate your point.

This first graphic is in reference to the scuffs/scratches. CZ's do scratch pretty easily. This is a stone that's been around a bit. In this graphic you can easily make out scuffs/abrasions at the facet junctions as well as scratches on the table.

Here's the facet pointing nightmare was talking about.'

CZ's are generally cut pretty sloppy when it comes to symmetry characteristics. Here is a cz alongside an AGS ideal cut to demonstrate the differences nightmare was bringing out.

Barry... that is a very good article. Thanks for posting it. Are we allowed to reference and link educational material in these posts? It was my understanding that there are no exceptions.

Peace,
Rhino

Rhino - thanks v much for adding those extremely clear pictures - compeltely clarifies what I was trying to say!

My pleasure nightmare.

Hi, I am curious about the Asha diamonds. Can you tell me the difference between a Asha CZ and a typical CZ and a real diamond? Thanks

I find this rather useful when looking at loose diamonds.
Never look at a loose diamond on a white jewelers'
tray. Always look at it on a piece of newspaper or
printed material. If the diamond is real, you won't be
able to read the newsprint through the facets; if the
diamond is fake, it's just like looking through, well,
glass.

also, in light, a cz is very white.

Back to the first post...what about under blacklights!??!?!

Ultraviolet lights are not a good test to decide if something is a diamond. CZ's, and most of the other popular simulants, are inert to UV light unless something has been deliberately added to the formula to cause it to fluoresce but most diamonds are also inert. If it doesn't glow under UV, it might be a diamond. If it does glow, it still might be a diamond.

Neil

The dot test worked good. But how about on an emerald cut stone?

Hi, i'm a new member here. i found all the tests very interesting and helpful. i have heard about the fogging test which is very quick and easy and which can be performed on mounted diamonds. wanted to know how acccurate this test is . here are details:

Put the rock in front of your mouth and fog it like you would try to fog a mirror. If it stays fogged for 2-4 seconds, it’s a fake. A real diamond disperses the heat instantaneously so by the time you look at it, it has already cleared up.

Hi Rhino, I have a question. What if the rock is actually mounted then is there another typr of test which could be done at home?

rhino , you rule my friend

Yeah you do rule...

So I just did the test and realized I got a CZ stone rather then a real diamond

Hehehe, I knew I was getting a fake, this guy sold it to me in a back alley in Phuket for $30 CAD dollars, he made a huge song and dance story about how it was real, then did a bunch of tests, 3 tests actually.. I talked him down from $500 USD LOL....

1st test, he scratched glass then broke it in half (common myth that seems to wow people).

2nd test, he placed a wood block on the ground, then a coin, then the "diamond" then another coin, then he made me smash it with a rock furiously.. It didn't break... Thats a show stopper right there... In fact the coins got all scratched up.

3rd and final test, he placed it into a gem holder, then lit it on fire for a minute or so with a lighter, it was fine..

Boy these CZs are really tough... I think I'll make it into an earring and whenever people ask, I will tell them the story about this allycat jewler.

Night folks,
adam

Thanks Rhino...You really rock..Its very easy....

Hi there forum newbie and also bought 3 diamonds in Thailand today, right up in the north


in a hill tribe village . . .  exactly the same speil and technique! I knocked him down to $60 for 3 as I was looking for diamonds for some earings for my wife.



Thought I try and find some info and bang! Here we are.



Many thanks to all for your input, I'm not into gems - so won't post again.



Have a good one



David (scammed!) - Northern Thailand!