Is A Cavity In Diamond Acceptable?

[wccn 0]

I see one SI2 diamond with a cavity...
will this has any structure issue or durability issue?
say the diamond will break after some years?

 

example:
GIA = 2176230480

[davidelevi 598]

Not likely: bear in mind that "SI" inclusions by definition do not impair significantly durability or transparency (otherwise they would be "I" grade inclusions). On the stone you specifically mention, the cavity is right on the girdle; this could actually be a blessing, in as much as a skilful setter should be able to put it against a prong and "cover it" that way. The downside of that is that it could chip while being set and in the longer run any dirt entering the cavity may become hard to remove.

[André Cadieux 0]

Hi David,

Appreciate your keen insight.  How about this cavity?  GIA 5343366266  

And would this be an unusual place for a prong?

Many thanks!

[davidelevi 598]

Hi André!

The GIA site seems to be down. I'll keep checking and hopefully at some point before Monday it will be up.

[davidelevi 598]

It's very close to the girdle...but below it, so I wouldn't worry about covering it with a prong - it will be hidden by the rest of the diamond. Most likely it would be not in a good place for a prong anyway, unless you have a setting with at least 5 prongs (it is a large stone!)

Edited June 26, 2020 by davidelevi

[André Cadieux 0]

Hi Dave!  Many thanks for the quick turn.  As rendered does this qualify a small cavity? With time/use, do you think it could present a structural integrity or observed clarity problem?  Would a co-located prong (however unorthodox for a pear) help protect it/reinforce its integrity.  Thanks again!

 

[davidelevi 598]

Sorry for the slow answer; I think I'm 4 or 5 hours ahead of you, and I went to sleep before you responded (I guess you are from Quebec?)

Bear in mind that a "real" answer to most of these questions requires actually seeing the stone, however we have some indirect clues:

1. It's likely to be very small. I could not see it on the plot, until I realised that what I thought was another "indented natural" sign was actually the cavity with a single cross-hatch line. A GIA plot is not technically "to scale", but they do try to represent relative sizes.

2. Observed clarity: considering location, and the fact that GIA placed it fourth on its list of characteristics, I think it's very unlikely you'd see it without a loupe; depending on the setting and how high the stone seat comes, you may not be able to see it at all once it's set.

3. Integrity - see my answer to the first post on this thread. Honestly - don't worry.

4. It's on the pavilion (bottom) of the diamond. It's protected by a mm of the hardest natural substance known... Also, unless you have a 5 (or more) prong setting it won't work mechanically to have a prong there: you need one (or 2) on the point, and 2 behind the bulge for the stone to sit securely; the cavity is in front of the bulge. Extra pairs of prongs can be set more or less where one likes, but unless you like the look there is really no reason to have them - the stone is big enough to "carry" them visually, but it is overkill mechanically if the seat is fashioned properly. I'd worry more about protecting the point of the stone!