Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
Did you look at it? I have personally seen clarity enhanced diamonds that I would grade I2 test as mossinaite because they were type II. These diamonds give a false positive on the combo diamond mossianite detectors. Gary Roskins did a nice article on this in one of the pat Gemworld Guide magazines.
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Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
Some time in the past I also had occasion to look at some Pegasus diamonds. They were the first HTHP diamonds on the market and were run through the GIA with no comments, because no one knew the treatment was on the horizon. The diamonds that were suitable for this treatment were also type II. Shortly after this the type II diamonds were skimmed off the diamond boxes (rumor I heard). Anyway, these diamonds were high color, high clarity after treatment. And some will also give false positive on testers which have the moissanite check feature. Alberto was right, it is big enough you should be able to id with a loupe.
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Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
A "Gem Lab" would be very remiss in only using a thermal probe for identification. Obviously, they also used magnification to notice that it was clarity enhanced.....it would have also been easy to see the double refraction.
Why would anyone glass fill a moissanite in the first place? Fraud? Maybe....but why is it not glass filled now?
Joined: Mon Oct 17, 2005 11:10 am Posts: 299 Location: Illinois
I think they (the lab) are probably correct. If a type II diamond which was HTHP treated was sent for a report, that was the report they provided. The diamond would not have shown any double refraction because indeed it is a diamond. Upon return to the client someone else used diamond probes and decided it was a mossinie, which makes sense because some type II will give a false positive. The person with the probe needs to put it down and use a loupe. No DR, no moissiante no matter what the meter says. Where is Dr. Hanneman when you need him?
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Joined: Mon May 14, 2007 11:00 am Posts: 1133 Location: Monterey, CA
John Fitzgerald wrote:
Where is Dr. Hanneman when you need him?
Don’t worry, I'm still here, laughing.
I solved the problem of moisssenite and all those other OTL gems some 35 years ago by creating the concept of LH. However, the GIA was either too stupid or too proud to understand the principles of the Lustermeter (Diamond Eye). See Gems and Gemology, Summer 1977, p 302.
Likewise, for the Hodgkinson Method, I created the concept of the B/D Ratio. See Lapidary Journal, 1980.
Reprints of both of these articles can be obtained by contacting Brabra ($!0 postpaid).
As for now, we are reaping the results of two generations of ill-informed wantabe appraisers who do not understand the principle of physics and need to push a button to have a Raman spectrometer spit out the answer.
Joined: Wed Oct 22, 2008 5:00 am Posts: 344 Location: Finland
The color of this stone is not in the typical range of HPHT-treated diamonds or type II diamonds, instead it is something which could be achieved by natural or artificial irradiation. The color matches perfectly with moissanite. One second with a loupe or 2 seconds with bare eyes (Hodkinson method) is all needed to solve the mystery.
I don't know this lab but would it be best not to bash a lab in public, when swapping a stone is something happening all the time. On the other hand I find it quite hilarious that the paper states the stone is Conflict Free. Do they only issue papers to known cutters having Kimberley certs for the rough? Do they observe the whole cutting process of each stone?
Bill, I have your original DiamondEye, yay I just push the button and it spits the answer, who cares about the physics
Joined: Thu Feb 22, 2007 10:23 am Posts: 923 Location: NYC
its very similar to the reports i have seen for sintered Black Diamonds that in their phoney report has been identified as "Natural Black Diamond" & in the comment of report it also said HPHT as treatment which is kind of true because for making sintered diamonds they use HPHT with diamond powder + Si and some metals like Fe, Ni. but its actually a man-made product and they took advantage of words like HPHT to make their report looks more genuine and sell their product as NATURAL. i bet there is no Lab doing this, they must be some greedy people making up the report and sell their product by a phoney report which is telling half truth and hide the rest of details in shadows of technicality lies, I think there is a similar scam but for selling Moissanite,
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