The jeweler says that the stone is a natural carbonado

Q: my girlfriend and I have been shopping for engagement rings, and found one that we're quite a fan of. The ring features a non-traditional center stone from a small husband-wife jeweler.

The jeweler says that the stone is a natural carbonado, and seems reputable; that said, I'd like some degree of confirmation that this IS indeed a carbonado. I asked about getting a certification for the stone, and the jeweler was fine with it, but said that it would require them to extract the stone and then re-make the ring.

As it's a one-of-a-kind piece, I'm a bit hesitant to do that in case it alters what we love about the design. Are there any ways, working with the jeweler or an outside party before purchase, to confirm the authenticity of the diamond without removing it from the ring?

A: It may very well be a Carbonado, but what gives the jeweler the confidence that it is one? When they bought it they would have to have been reassured that they were getting the real deal.

The International Gem Society tells us that while most black diamonds on the market today are either superheated or irradiated to an almost black color, natural black diamonds do exist, though they are extremely rare. 

Black diamonds are as a rule not more expensive than colorless diamonds.

For reference see this 3 carat oval from one of the world's foremost experts on fancy color diamonds. https://www.leibish.com/black-diamonds/fancy-black-oval-31234

As you can see the above site provides a GIA certificate with their diamonds.

Without one it is better to assume that it is a treated stone. Just check amazon.com and see how much black (irradiated) diamonds go for.

Some tests can not be done , such as specific gravity comparison of the weight of the isolated stone to the same volume of water. This test only proves it is a diamond, not whether it is a natural Carbonado,

However it's up to you. What is the significance of knowing that the diamond is what it's purported to be? Satisfaction, yes. But insurance and resale value could be factors for you. Will the in-house certification cut it for those? Maybe. But GIA holds a lot more authority.

Q: This is really helpful, thanks for the feedback. This particular ring is only about $2.2k, and the center stone is 1 carat, so that's less than the cost of most colorless diamonds I've seen. As far as I can tell, they have confidence in the authenticity on the word of a sourcer that they trust.

In your opinion, it sounds like I should go with the certification?

A: Without certification you may as well buy an irradiated stone. This is what certification is for. So you can be certain.

Q: Thanks so much, that makes complete sense.

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Help Choosing a Cushion Cut Diamond

Q: I've been looking at 8 faceted cushions (as opposed to 4) and narrowed it down to these three. I've looked at them so much that they look pretty much the same...

any opinions?? This will be on a white gold pave band. Each diamond is around 3.7k

A: That first one looks pretty amazing for an SI1. If that's correctly labeled then you have found yourself a nice stone. The grading report usually has a bit more information on the type of inclusions than can be made out from the photo. Did you get a chance to look at the lab reports?

Q: Yeah, I have the GIA reports. Once it points out the inclusion, I can't unsee it!

Here's the report.

and here is the side and bottom views. I figure my girlfriend will never see it from the bottom, so those inclusions aren't that big of a deal.

A: Yep. But at least you know it's legit. Seems like you found a sweet deal. All the best.

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Cushion Cut Purchase Recommendations

Q: Hi, I was wondering if you could help me. I'm looking for a cushion cut diamond in the 9-10k range. Obviously if I can find something exceptional for less, I may want to put that difference into a possible three stone setting. Do you have any tips for finding good value? Can you explain diamond fluorescence?

A: The cut quality of Cushion cut diamonds is not as easy to determine from a grading report as round brilliant or princess cuts.

Browsing online jewelers that have high resolution images is a must. However if they don't display an image many jewelers will be able to send you an image upon request.

Like this one:

 https://www.briangavindiamonds.com/diamonds/diamond-details/1.130-e-vvs2-cushion-diamond-gia-5203482808

Diamond fluorescence basics:

When under ultraviolet light, fluorescent diamonds glow.

This effect looks pretty awesome in a nightclub.

In daylight, though, the glow sometimes interacts with the light that would make up the diamond's fire and brilliance, essentially reducing its sparkle.

The result is a reduced brilliance in daylight.

This does not occur in every single fluorescent diamond.

But it is not possible to be certain unless it has been previously checked.

One jeweler that screens fluorescent diamonds is Brian Gavin Diamonds. https://www.briangavindiamonds.com/diamond/brian-gavin-blue-diamonds-with-fluorescence/

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