Ring head size

[AprilBaby]

If I have a 8.65 mm stone what size head do I want to get for a solitaire? 8.5 or 9 mm?

 

[marymm]

Well, if it is the typical 4 or 6 prong head, you could probably go with the 8.5mm *if* the stone's depth is average-to-shallow ... if it is deeper than average (as many colored stones can be), then I'd go with the 9mm.