Tension setting looks oval?

[Erasmus]

I've been looking at a number of different tension settings, both online and in B&M stores. So far as I know, all of them have had CZ stones. I recently had occasion to see a lady's tension-set e-ring by Gelin & Abaci with a real diamond, and was shocked to see that the stone looked oval! Apparently, they had to groove the sides of the setting (yellow gold) so much that the setting obscures the sides of the stone, giving the RB an oval appearance. None of the CZs I'd seen before had ever looked like this (and I'd seen the exact same setting), and certainly not in the on-line catalogs.

Having recently sent my stone off to be set by G&A, I'm a bit disturbed. Is this normal? Frankly, the appeal of the setting was that the entire stone was visible; having a portion of it obscured is not what I was expecting at all. Not sure I'm going to like my setting if it comes back looking like hers!

(If it matters, the stone I saw was reportedly about a 85 pointer.)

 

[Mara]

Actually I have seen tension set rings with actual oval stones. IMO they look better than a round in a tension...but I don't like that there are no H&A ovals...hee hee.

Not too sure on your other Q but are you sure it wasn't a real oval stone?

 

[Erasmus]

The stone was reportedly an 8*, so I hope for her sake it wasn't oval to begin with

 

[boonerings]

There are grooves in the side walls that hold the stone in place. They are normal to all tension sets I am aware of, and are in all the ones I make. They are cut with a diamond shaped cutter so that the stone nests in them. The stone would not be secure without them and would be stressed quite a bit more. The grooves aren't too deep, about .015" to .025" per side depending on the stone size.

 

[Erasmus]

Wow, that's a non-trivial amount for a stone that's only ~6mm in diameter to begin with. Taking a whole mm out of the stone definitely gives it a different look. Why don't they mount the CZs in the showcases in the same fashion? Seems like a little bait & switch to me...

 

[boonerings]

They probably have the same machined grooves, but CZ's being CZ's probably have a wider girdle, so they may not seat as far in the slots. Different designs need different depth of those grooves. I have seen very shallow grooves, but there is obviously a bit more risk of dislodging the stone with a side impact. It could be that if a ring was designed for a CZ, it is deemed to be relatively easy to replace, so less of a safety factor is needed. CZ's can't stand as high a tension as diamonds can though, so you would expect the slots to be deep for those too.

 

[Griffin]

I do tension set pieces all the time, and they do not have the issue you speak of, but the settings I use are each created for the specific stone in which they will be set.

If the jeweler was trying to fit a stone into a generic ring meant for a smaller diameter stone (i.e. a .85 stone into a setting meant for a .75), or if they were unfamiliar with tension sets, the problem you mentioned can occur.

Creating the mounting for your stones size in the wax before casting, or casting the stone in place (my favorite), will virtually eliminate this problem and create a much more secure mounting with very little metal occulting the stone.

 

[valeria101]

Griffin, but even in the closest matching setting, one would still have to put some metal over the girdle of the stone, isn't it? I frankly doubt that those <0.03mm show that much. Would one frequently see less well-made rings with much more of the stone sunk into the tension setting?

 

[Griffin]

I guess it all depends on the mounting as well as what the jeweler feels comfortable with.
A heavier mounting or a more rigid material, or both, will be less likely to flex and lose a stone upon impacts, and therefore can have shallower grooves.
Size of the stone makes a big difference for mounting flex as well.
The shape of the mounting affects it, too. A curved tension set for an RB, for instance, can occult a stone far less than two parallel walls where the grooves must be deeper, as they would only contact at two points.
Mounting method counts as well. For instance, cast in place allows for very little occultation and is a superior method in some settings, while different hand setting methods are superior with others.
There are just too many variables for a simple answer...