# A good diamond tester



## Danielle (Feb 20, 2012)

Hi there,
Can anyone recommend a good diamond tester. 
I was using the Culti Diamond Selector II which I was happy with. After about a year the machine broke and I ordered another from Ebay. However, it looks like I ordered a fake! (looks exactly the same but does not have the culti logo on the front). This one does not work as well. Now it seems that I cant find a genuine Culti anywhere.
Does anyone have any good experiences with a relatively inexpensive machine? (the original one I bought that worked well was under $50).
Any advice much appreciated.
Thanks,
Danielle


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## philddreamer (Feb 20, 2012)

Hi Danielle!

I use a "DIAMONDNITE DN-1" by Oris Nelson Enterprise, Inc. I bought it a couple of years ago from IGEM Instruments, www.igem.com ; I'm very happy with it. I also bought a Mizar-24 gold tester at the same time, so got a little discount. 
I made my money back... and then some! 8) 

Take care!

Phil


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## Danielle (Feb 21, 2012)

Thanks Phil

Danielle


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## qst42know (Mar 14, 2012)

Is this what you are looking for?

http://www.amazon.com/exec/obidos/ASIN/B005KV485M/buttonlink78-20

Or are these the knock offs?


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## nickvc (Mar 15, 2012)

As a post script to your request if you know nothing about diamonds and are buying them make sure you have a tester that differentiates between diamond and moisanite or it will be an expensive mistake, it's not so bad if the stones come for free but that's rare unless they are very small these days.


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## Dan Dement (Mar 20, 2012)

Guys,

Just for all to know, today they coat moissettes using a Diamond Vapor process that moissettes read as diamonds on the top but are still moisettes. I have only seen a couple of them and they are coated on the top only (so far) but you need to learn! Diamonds are single refractive and Moisy's are double refractive. This means when you look at the culet which is the bottom point, you see a slight doubling. If the stone is loose and you have a diamond scale and it is round, the moissy will weight about 10% light. The formula for figuring weight is Diameter x Diameter X Depth x .0061 which will will get you close. Moissy's today are a Top Light Brown Color and weight about 10% less than a diamond. Note that all of these I have seen are in the 6.00mm size up.

Like refining, Diamond buying can be dangerous but to your pocketbook!

Dan

This subject, I know about!


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## Oz (Mar 20, 2012)

Dan,

Are you saying that moissettes that are diamond vapor doped become single refractive? Or does the doping just allow them to be conductive when tested across the table.


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## philddreamer (Mar 20, 2012)

Hi Oz!
I understood that if the moissettes have been doped, if one was to use a "DIAMONDNITE DN-1", for example, the "DIAMONDNITE DN-1" will give a genuine reading.
But, if one was to use a loupe magnifier, one could be assured of the diamond's genuiness by the true diamond's single refractive. And another way would be by the weight.

http://www.ajediam.com/diamond_clarity_grading_chart.html

I hope I understood Dan correctly.

Take care!

Phil


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## Dan Dement (Mar 20, 2012)

OZ,

What I am saying is that they "dope" the top of Mossy's to give a false reading on Diamond Tester much like you would gold plate silver. The Diamond Tester is going to call it a diamond as most are thermal testers. How do you tell? First test is to look at the Stone and see if it is SR OR DR? Single or Double Refractive! Second indictation is Stone a Top Light Brown as Mossy''s are fairly brown. Third way is to take it out of the mounting and check the bottom. The few that I have seen are only coated on the top but I do not deal in them so I could be wrong. Fourth way is to have an accurate diamond scale and weight the diamond. Using the Formula of Diameter Squared x Depth x .0061 will get you very close on a ROUND diamond. Mossy's weight about 10% light. 


The learning curve is very quick on losing your money. Just saying you can not depend on using a Diamond Tester as they can be fooled! 

Dan


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## Oz (Mar 20, 2012)

Dan,

It was my understanding that moissanite is indeed thermally conductive as diamonds are. However I thought that moissanite are not as electrically conductive as diamonds, this is why I asked as to the “doping” across the table and if it changes the conductivity of the stone (meaning electric conductivity).

I understand the mass difference, but it would only be time effective on larger stones I would think, and with a very accurate scale. Would you happen to know how small of a stone the moissanite is available in? Is it still just the 1 company that produces these?


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## Dan Dement (Mar 20, 2012)

Oz,

I have at least 5 different CZ/mossy type tester and I believe they are all based on thermal conductivity and not electrical conductivity. Now, most diamonds do not conduct electricity except Type IIB diamonds which are what the Natural Blue Diamonds.Many years ago, there used make a meter made for testing the Natural Blues like the Hope diamond. Now, Usually I don't need toys to separate natural diamonds from CZ's or Mossy's but when you got 300 carats of break out diamonds and baguettes are especially fun for these old eyes. To answer your question, I really don't see the small stones Mossy's like you do in CZ's/ I buy CZ's down to 1mm stones as I sometimes make copies of designs in Silver/Pd of rings that I have made. I don't see Mossy's under .50cts but I am not a fan of them either! Way ovr priced and not worth the money IMHO. Bet way to separate small melee is to soak in HF for about 15 minutes. CZ's frost and HF has not effect on diamonds. I do not advocate HF as you know it's pretty dangerous without the proper precautions. I did just Google Moissanites and Moissinite .net is selling .02 ct for $12.50 so I guess they do make them. Of course, I got lota of melle I will sell you at 1/2 that price. When you read all the hype over Mossy's, dont forget Abraham Lincoln's famous quote: Dont believe everything you read on the internet! 
Dan


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## nickvc (Mar 21, 2012)

Dan I have seen a few moissanites and all the ones I have seen I would say have a greenish tinge rather than brown. Most of the stones are easy enough to spot if you deal with diamonds fairly regularly but can fool the novice or those not aware but to me just don't look right, experience I guess, the best con I saw came from a friend who was offered an old diamond ring with a large old cut, it's not unusual for old cuts to be off colour but his one didn't seem right and right enough it was a moissanite....buyer beware!


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## Dan Dement (Mar 21, 2012)

Nick,

After 40 years in the jewelry business and over 30 years in teh Diamond business, I have seen lota of them. With a retail store, we see all sort of scams and are pretty good at catching them. Of course, there always someone coming in something new and the two I just saw actually came from another Jeweler friend who wanted me to look at them. Just like in refining, there is no easy button. We have learned to check every Princess cut diamond for broken corners when they come in. Nothing like experience and Experience using your own money is a pretty quick teacher! I am not the smartest guy on the forum but I have just tried to learn from my mistakes! 

Dan


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