How do you know a flawless diamond is not lab grown?

[PureDiamonds]

I've been researching the differences between natural and lab grown diamonds, but the examples all seem to apply to included/colored diamonds. Or they assume the lab grown has some manufacturing defects. I haven't been able to find a great answer to this yet.

So if I've got a D/IF diamond, how can I be positively sure that it is not lab-grown? What scientific techniques are available that can do this?

 

[headlight]

You can start with a grading report from a reputable gemological lab, such as GIA or AGSL.

 

[PureDiamonds]

I mean if you don't have a nice inscription or grading report. I'm sorta curious about the scientific aspect of it.

 

[distracts]

If you check in the lab grown section, there are multiple posts linking to articles. If you ask, people who regularly check that part will be able to link to more, I'm sure.

 

[whitewave]

@John Pollard

 

[flyingpig]

Type IIa testing. I think..

 

[John P]

All synthetics in the normal range will test as Type IIa, but only about 1-2% of natural diamonds are Type IIa. This means type testing is sufficient to identify the vast majority of diamonds as natural, and will ID those needing further analysis.

There are other context clues. Some are based on inclusions. Remember that "IF" is a judgment made at 10X. Zoom in farther and more can be revealed. Other clues are based on growth fundamentals.

More information here.
https://www.hpdiamonds.com/en-us/extra/172/laboratory-grown-diamonds

 

[PureDiamonds]

I was actually wondering this after seeing the articles on that site! How zoomed in were those pictures taken and what grade were the example diamonds? I guess I'm wondering because wouldn't an extremely high quality lab grown lose all of those features? No colors, no inclusions, no banding, no flourescence etc. Naturals can also come in type iia so isn't that not a positive method?

 

[whitewave]

I was actually wondering this after seeing the articles on that site! How zoomed in were those pictures taken and what grade were the example diamonds? I guess I'm wondering because wouldn't an extremely high quality lab grown lose all of those features? No colors, no inclusions, no banding, no flourescence etc. Naturals can also come in type iia so isn't that not a positive method?

In one case, GIA requested proof of Kimberly process etc to track the diamond to the mine