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Verification By Someone Who Knows

Devin Skipton

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Hello my name is Devin. i am in afghanistan and i bought some diamonds for an engagement ring. they all came with certificates but i want to know if they are legit .... IGITL International gemological Institue and testing laboratory (INDIA) and GLI Gemological Laboratory of India.



Variety- Natural DIamond

Weight- 0.47 cts

Color- White, Yellow Tint

Shape/Cut- Round Brilliant

Measurements- 4.98x4.94x3.11mm

Refractive Index- 1.79 over range




Variety- Natural DIamond

Weight- 0.52 cts

Color- White, Brown Tint

Shape/Cut- Round Brilliant

Measurements- 5.03x5.02x3.18mm

Refractive Index- 1.79 over range



Shape&Cut- Round Mixed Cut

Weight- 1.62 cts

Measurements- 7.54x7.52x5.04mm

Color- Black

Optic Character- AGG----(what is this)

Refractive Index- OTL-----(what is this)

Microscopic OBS- N/A

Specific Gravity- 3.05

Species- N/A

Comments- Cryptocrystallline Variety



Can any one give me an approximate value or a guess from their experience.... and if there are any experts can you please tell me what these diamonds are lol... i dont know much and i had them made into a ring for my new fiancee but before i go home i just want to learn about them thanks and will be looking for a response.

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Hi Devin,


Thank you for your service. Please come home safely.


I've never heard of either lab. This dosn't make the stones fake or necessarily a problem but no, I would not call the 'certificates' legitimate. The big issue on fancy color diamonds is the origin of color. They call it 'natural diamond' but don't mention the 'untreated color' so I think it's fair to assume that all 3 stones have been treated. In those color ranges it's not a huge deal like it is with pinks and a few others but tiny details make a big difference in this business.


AGG stands for Aggregate

OTL means Over-the-Limit of a standard gemological refractometer

Neither stat is relevant.


There's not enough info in the picture to tell if they did a nice job on it or if they're correct about the metal type.


Prices vary a lot with the above details and the market and 'value' varies with how you define the term. I see treated black diamonds being traded on ebay for about $100/ct. Sometimes a little more, sometimes less. That seems to be the biggest marketplace for them. HPHT yellows in that size range vary a lot with clarity but figure $200 per carat on those. Untreated fancy browns are usually a few hundred per carat. We just don't know. The range is pretty high on these depending on other details not provided. The fact that they don't say much on the 'certificate' is a bad sign. 14k gold costs about $40/gram and assembly labor ranges from a few dozen to a few hundred dollars depending on who you have do the work. If I had to guess from the picture, I would expect about 5 grams.

Edited by denverappraiser
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I didn't total all of it up but that seems a little on the high side. Again, it depends on the details of those two side diamonds and the mounting itself. 2/3 of your money is in those side diamonds. It's not out of the question but more information would be required to really figure it out.

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AGG = aggregate. Multiple crystals in one "rock".

OTL = Over The Limit of a traditional refractometer (~1.80; diamond RI is 2.417)


It is very likely that you have three diamonds; the only way to ascertain this is through direct inspection - no amount of photos will do. Whether you paid a fair price for them is a completely different questions, and chances are you haven't (the US retail diamond market is more competitive than anywhere else in the world). Neither is it possible to estimate - even roughly - a price/value: the information provided in the lab reports is not sufficient to establish fair comparators (nor does it tell you whether the black colour in the main stone is natural in origin or not: this alone makes for a factor of 10 in price). Sorry.


ETA: started writing this before I saw Neil's posts...

Edited by davidelevi
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AGG doesn't matter for a black diamond; in fact, if it has been treated to become black it is because as an aggregate it was not going to become a very nice transparent gem. OTL of a traditional refractometer is expected in diamonds, but it means nothing: CZ is OTL too, and so are most other diamond simulants.


Neither will have any impact on the stone's value, if this is what you are asking.

Edited by davidelevi
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An "original afghani black diamond" would be a very interesting thing. I'm sorry but he's leading you down the garden path - there are no diamond mines in Afghanistan (the geology just isn't right), though you may find some lovely tourmaline and lapislazuli there. That doesn't mean you aren't getting a diamond, but it is most likely treated and definitely not Afghan in origin.

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