Pave set diamonds - how thick does the metal need to be?

[glowpear]

Evening all,

This is not my first post, but I have since read that it is good form to introduce yourself before posting so apologies for that. I am a hobby gold and silversmith of a few years on and off and I live in Hamburg, Germany. I have a small workshop space that I use once a week, I am mostly self taught and I do courses when I can although my 8 month old daughter is keeping me a bit too busy for any nice, interesting courses at the moment! My question is to do with pave set stones, which I don't have any experience of to date.

I am looking to bezel set a gorgeous cushion shaped cabochon aquamarine stone that I picked up at a trade fair recently. I am looking to set the stone with a lip protruding from the base of the bezel cup to allow for a small row of pave set 1-1.5mm diamonds (not yet purchased), which I cannot do myself and will take to a professional setter to ensure results. What I would like to know from one of you knowledgeable sorts is how thick the metal for the back of the bezel cup needs to be? The setter I spoke to was spectacularly unhelpful and with the price of gold being what it is I want to keep my costs as low as possible. With such small stones I would expect the diamonds would not need to be open backed, but I don't know if there are any other factors I need to consider with pave set stones. I have checked my books and done some searches online but I am not feeling very confident.

Does anyone have any thoughts?
Thanks in advance.
Glowpear.

[Dennis]

Well I am not sure that I understand the problem, so at the risk of stating the obvious the metal must be thicker than the height of the stone from table to culet. In other words, buy the stones first and measure them. Dennis.

[ps_bond]

For that size of stone you'd be looking to have the table level with the surface; if you want a closed back setting then obviously you need the metal thicker than the total height of the stone. However, depending on your design, you might be able to get away with 0.7mm - that'll leave the culet just protruding, but will provide enough metal to give an adequate seat. Thinking about it further, you could probably set 1.0mm into 0.5mm reasonably, but I'd prefer not to...

If you want your chosen setter to suggest a suitable thickness, ask them if they're happy setting into 0.3mm
(Actually, there is a useful way to do that using blunted burrs - it displaces the metal and gives a greater effective thickness)

[glowpear]

Thank you, Peter, that was exactly what I wanted to know. I don't know anything about Pave setting and assumption being the mother of all screw ups so wanted to check with someone who had done this sort of thing before so I can buy the stones and metal with confidence. As it seems to be more a design issue I will have a play in cheap metals and see what works. Thanks very much!

[glowpear]

PS Dennis sorry if the question seems stupid to you - I am working completely alone with no one to ask these things of, so I really appreciate being able to ask the forum so I can make progress with my designs. Thanks!

[ps_bond]

You're welcome! If I've understood you correctly, then your limitation is probably more the strength of the edge of the setting as it'll be exposed?
Oh, and if you're doing the layout for the stones, remember that if you're setting into a convex surface, the centres need to be fractionally further apart at the top of the plate so that they end up girdle to girdle when seated.

[glowpear]

Super stuff Peter, thank you very much. I am just going to concern myself with the metal work and leave the setter to do the layout and supply the stones. I have great respect for this kind of stone setting and in order to look professional I think I will leave it to a professional! Your help is hugely appreciated, thanks.