Would a lab grown diamond report indicate coating as a “post-growth treatment?”

[oncrutchesrightnow]

Saw this diamond and thought it might be coated. Lab report just says “post growth treatment.”




Maybe this diamond is not coated and it just has a white inclusion and blotchy color zoning. But asking theoretically… Do reports for LGD put coating in the same “treatment” category as irradiation or heat? Can we rely on reports to say a stone is not coated? We can at least rely on reports to say stones are a diamond through-and-through versus a LGD-coated moissanite, right? Not implying anyone did anything bad here. Just trying to help everyone make informed choices, especially folks who like collecting weird stuff.

 

[Garry H (Cut Nut)]

You have the video - please attach a link Crutches.
It appears that the white inclusion is actually an open crack on the stones table. If that is the case then there is no evidence that there is a coating.

 

[Karl_K]

cvd blue blue = nuked + heat treating

 

[DejaWiz]

Here's the Loupe360 video:

Loupe360

loupe360.com

 

[Garry H (Cut Nut)]

Here's the Loupe360 video:

Loupe360

loupe360.com

You are amazing DJ
Yup, it is a wide open surface crack (trade jargon to confuse consumers = feather).
So there is no evidence that the white space is anything other than a wide open crack.
FYI - to tell if an inclusion reaches the table, if there is no doubled image (internal reflection from the table) it is on the surface - the white diamond pic below is internal:

 

[oncrutchesrightnow]

Thanks, guys.

Appreciate your help @DejaWiz The website where I found the diamond only gives videos after you request them.

@Garry H (Cut Nut) Why is the crack white? I thought heat/radiation changed the diamond color through and through but are all the color treatments only surface treatment? Or is there some optical property that makes the light returned from the crack in an irradiated/heated diamond look like a different color than the rest of the diamond?

‘Ok so just to be sure, @Karl_K , if a LGD has an IGI report that says the diamond is CVD with “indications of post-growth treatment,” that would NOT include coating, right?

Again, thanks all.

 

[Garry H (Cut Nut)]

@Garry H (Cut Nut) Why is the crack white? I thought heat/radiation changed the diamond color through and through but are all the color treatments only surface treatment? Or is there some optical property that makes the light returned from the crack in an irradiated/heated diamond look like a different color than the rest of the diamond?

‘Ok so just to be sure, @Karl_K , if a LGD has an IGI report that says the diamond is CVD with “indications of post-growth treatment,” that would NOT include coating, right?

Again, thanks all.

I think it is just reflecting the bright white lights from the video set up

 

[Karl_K]

‘Ok so just to be sure, @Karl_K , if a LGD has an IGI report that says the diamond is CVD with “indications of post-growth treatment,” that would NOT include coating, right?

I have reached out to a contact at IGI to try and find out how they would report it. It may take a while to get an answer.
The diamond in question is not coated, its nuked and heat treated.

 

[Karl_K]

@Garry H (Cut Nut) Why is the crack white? I thought heat/radiation changed the diamond color through and through but are all the color treatments only surface treatment? Or is there some optical property that makes the light returned from the crack in an irradiated/heated diamond look like a different color than the rest of the diamond?

I agree with Garry it could be a reflection.
It also could be the color change did not take on the open feather area for some reason.
Or it could be something in the crack.
Weirder stuff has happened.

 

[oncrutchesrightnow]

Good information, appreciate the help.

ETA: stills of the crack… shows it is white at different angles…

 

[Karl_K]

I am sorry I posted this in the wrong thread earlier.

Here was the reply I got from my contact at IGI.
"IGI will not issue a ND or LGD report for stones with non-permanent treatments like dyes, coatings, etc.
To be permanent a treatment must alter the stone at the molecular level."
IGI link that talks about treatments:

https://www.igi.org/gemblog/are-post-growth-treatments-permanent/
Just for fun, chicken treatment/cleaning for gemstones and pearls.

https://www.igi.org/gemblog/chicken-cleaning-and-heat-treatments-what/

 

[oncrutchesrightnow]

I am sorry I posted this in the wrong thread earlier.

Here was the reply I got from my contact at IGI.
"IGI will not issue a ND or LGD report for stones with non-permanent treatments like dyes, coatings, etc.
To be permanent a treatment must alter the stone at the molecular level."
IGI link that talks about treatments:

https://www.igi.org/gemblog/are-post-growth-treatments-permanent/
Just for fun, chicken treatment/cleaning for gemstones and pearls.

https://www.igi.org/gemblog/chicken-cleaning-and-heat-treatments-what/

Thanks, that was helpful.