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Multiple Qs: CVD, post-growth treatment, gray in store light

kassia

Rough_Rock
Joined
Jan 2, 2021
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10
Hi PS!

Long-time lurker, first-time poster.

DH and I are planning to purchase a MMD. I've done a lot of research and read the MMD education article here, but I still have a couple questions. If it helps, I am an "eye clean" person, not a "mind clean" person, and we're buying this diamond for me to enjoy wearing.

1. I get the sense HPHT is preferable to CVD because of the color issues; however, I've also read here that as long as you're working with a reputable person who vets the stones you can still get a good CVD diamond. DH and I are hoping to buy from Distinctive Gem, and it's my understanding that Jonathan has high quality control standards and we could trust that a CVD stone from him would be ok. Do I understand this correctly?

2. IGI reports now indicate if a CVD stone "may" have gone through post-growth treatement. Is post-growth treatment a negative? If so, why?

3. I know IGI is a good cert. for MMD--are there other labs that are ok too?

3. We looked at diamonds and settings at a jewelry store to get a sense of size and style. In one case, the salesperson set a MMD into a setting that had mined sidestones and the contrast was very strange--the MMD looked like a steel gray whereas the sidestones looked lush and white. When I pointed this out, the salesperson said it was how the MMD performed in the store lighting. She walked me over to the window--in natural light, they all looked the same, a bright sparkly white. Does this happen with all MMD? I didn't really like the thought of my diamond going gray every time I was in LED lighting...

Thank you so much for any insight!
 
I have several MMD from DG, all CVD, and they are beautiful. No tint, no strain, just beautiful.
 
I would trust DG’s opinion if it’s a good CVD, and for what it’s worth my center stone is a CVD and I can’t see any stria with the naked eye.

On your fourth point, were you looking at a round brilliant center stone? If so it could be one of two things - well cut round diamonds do go greyish in direct sunlight and perhaps some other instances. LED, I’m not so sure. It could also be that it was an HTPT diamond and in that case, some of them can be grey or blue tinted. @DejaWiz is particularly good at spotting this. However, MMDs perform the same as mined diamonds, save for potential tint.

As mentioned, I would trust DG to source a gorgeous, well cut stone for you (I haven’t worked with him, but he has wonderful reviews all over PS), but if you post specs here of what you’re looking for (cut, 4C ranges, budget, etc) I’m sure you’ll get some great suggestions.
 
IGI, GIA, and GCAL are all predominant LGD graders. AGS does also, but finding one is nearly impossible.

Cream of the crop grading report would be GCAL 8X, due to their extremely tight specifications to meet their 8X criteria.

I highly recommend that any LGD be assessed for tint, but especially CVD because of other issues such as striations and potential birifrengence.

CVD that needs PGT to improve clarity and color, in my mind, indicates inferior rough and should be professionally vetted or avoided if that's not possible.
 
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I can’t imagine a well-cut MMD looking a different a color than earth-mined stones set next to it. Unless there are actual color differences. An H MMD with no color doping or blue nuance should look exactly the same as an H earth mined diamond.

Oftentimes with side stones or shoulder stones set at different angles and with a different cut than the center stone, you will see what looks like a color difference. More often than not, it’s just a difference in the angles of light and behavior of different cuts, especially if all stones have the same (reputable lab) color grade.

Rounds can grey out in lots of different lighting.
 
You should have no issues with Jonathan vetting your diamond. I purchased a CVD diamond from him and I'm extremely happy. If properly vetted, no stria should be visible to the naked eye. I have a G color that is extremely white with no post growth treatment, and a GCAL report. Just talk to Jon about your concerns, tell him exactly what you are looking for, and he'll make it happen. Enjoy the process.
 
Thank you so much everyone! This is reassuring! Very excited... :-)
 
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