Question about inclusion in princess cut

[TabitaW]

Hi all,

I would like to ask a question for "educational" reasons only, I'm still a newbie but I find diamonds interesting and I want to learn more and more.

The question is regarding my .32 ct princess cut diamond, F color and SI1 clarity. I got it a couple of years ago, pre-PS and it has no certification so I'm sorry but I don't know anything else about the diamond specifications. The thing I do know is that three different jewellers with good reputation have seen it and told me it is a very nice stone, true to color etc. They also find the stone very nice when it comes to sparkling, they say it seems to have a very good cut (but of course, it's just from seeing it mounted in the ring.) (I bought the ring with the stone very cheap, I have got it valued at 3 times the money I spent, good for me.)

Now my question: I bought it as SI1 clarity and it has an inclusion that looks like a slight streak of grey smoke (probably not preferrable at all),but it's only visible from the side view. The jewllers cannot find any other inclusion whatsoever in this stone, besides that streak they cannot find anything when using a loupe. And watching it face up you cannot see any trace at all of the inclusion and this is what amazes me, it totally disappears!The jewellers agree, they can only see it from the side. Is this due to the diamond cutting, meaning that the inclusion are placed so lucky that the facets "hides" it from that angle? In that case, can a diamond cutter "plan" those things, is this a matter of skills or is it just lucky circumstancens.

For me it's almost like a bonus, the stone feels personal with its little flaw, like something only I know of since you cannot see it if you don't look for it. And since I bought it cheap I knew it was a risk and then it's always nice to know it was better than expected (even though I know many of you wouldn't look twice after a stone like this).

 

[Karl_K]

Now my question: I bought it as SI1 clarity and it has an inclusion that looks like a slight streak of grey smoke (probably not preferrable at all),but it's only visible from the side view. The jewllers cannot find any other inclusion whatsoever in this stone, besides that streak they cannot find anything when using a loupe. And watching it face up you cannot see any trace at all of the inclusion and this is what amazes me, it totally disappears!The jewellers agree, they can only see it from the side. Is this due to the diamond cutting, meaning that the inclusion are placed so lucky that the facets "hides" it from that angle? In that case, can a diamond cutter "plan" those things, is this a matter of skills or is it just lucky circumstancens.

It could be a few different inclusions, twinning wisp, cloud or feather would be the most likely.
Did they say what it was?

Yes it is planned, now sometime luck comes in and they planned it the best they could and got lucky that it turned out even better than expected but without the planning they would not have got lucky.

 

[Amour_Et_Diamants]

It sounds like it could be a feather, and I've read that a good diamond cutter can plan to disguise inclusions. Hopefully someone with more experience can provide you more information.


Edit- NM looks like Karl K posted at the same time with much more detail

 

[John P]

Now my question: I bought it as SI1 clarity and it has an inclusion that looks like a slight streak of grey smoke (probably not preferrable at all),but it's only visible from the side view. The jewllers cannot find any other inclusion whatsoever in this stone, besides that streak they cannot find anything when using a loupe. And watching it face up you cannot see any trace at all of the inclusion and this is what amazes me, it totally disappears!The jewellers agree, they can only see it from the side. Is this due to the diamond cutting, meaning that the inclusion are placed so lucky that the facets "hides" it from that angle? In that case, can a diamond cutter "plan" those things, is this a matter of skills or is it just lucky circumstancens.

It could be a few different inclusions, twinning wisp, cloud or feather would be the most likely.
Did they say what it was?

Yes it is planned, now sometime luck comes in and they planned it the best they could and got lucky that it turned out even better than expected but without the planning they would not have got lucky.

It sounds like a pretty princess.

I agree with Karl on the above. A twinning wisp can look like the condensation trail behind a jet, which may be the smoke-streak you describe. TWs also form in a diamond's growth plane so they can be be less visible in one orientation than another. It must be visible in darkfield at 10X to be judged SI, but we live in the real-world so you get to enjoy a totally clean diamond.

RE Cutting: Yes indeed, rough can be oriented so inclusions become transparent or less visible face-up. Different operations treat this differently and value is always a consideration. But if doing this doesn't drop yield below a certain threshold or prevent a larger plan, we'd choose to improve the look. It also concerns the starting rough. In this size-category your diamond may have been a "toppie" (the remaining rough from a starting-crystal which produced a larger primary stone or stones) or a makeable (a crystal that didn't need sawing), where there may be more latitude to do this.

The faceting choice also played a role. Brilliant and mixed/princess cuts are designed to promote dispersion and scintillation face-up. This means inclusions are frequently more visible from the side. It's possible, had your diamond been polished into a step-cut, that the inclusion would be more visible from the top in those long transparent facets. So you can celebrate its princess-ness.

Without meeting the cutter there is no way to know whether it was planned, a happy coincidence or a bit of both, but I'd say it all works to your benefit.

 

[TabitaW]

Thank you so much for your help, I'm grateful and also impressed that you spend time and effort on newbie questions like this!
The more I learn about diamonds, the more impressed I become of people working with diamonds (cutting etc.).

Later I will have that ring, among a couple of other rings I have, valued for insurance purposes, then I hope I can get more accurate statements regarding the inclusions, it will be interesting.