Designing Prongs for Jewelry

I made a tiny key necklace for my girlfriend, I first had it made from plastic. Now I would like to go with one of the silver or brass options and I would like to add a Black Pearl to the top of the crown piece. However, I believe I must create the prongs to hold the pearl in place.



My question is, what are the design constraints when designing the prongs? I imagine that the thickness would likely be less than the required wall thickness. I'm not sure how to design these prongs and what my approach should be.

Thank you.

I just made my prongs the minimum wall thickness in silver. It hasn't arrived yet (.. a few days late actually, and still hasn't shipped, but I digress)
But if you actually consider how thick 0.8 mm is, you'll probably find that it's not too big at all.
Like 1mm is thin. Less than that is thiiiin, and any thinner you'd probably have breakage issues in a soft metal like silver.

So if I make the wall thickness of the prongs ~.8mm, then it would be sufficient? The prongs would have to bend to grasp the pearl. How far would the prongs have to travel up the pearl?

Thank you for your insight.

Hmmm I just designed some prongs/fittings for small rubys (5.5mm rubys) last month, on a pendant. They looked pretty good when we got the completed pendant back. I made the prongs 1mm wide, 1mm thick, and the right shape & spacing to fit a 5.5mm ruby (one of the standard gem cuts, 'round' cut). We used the HIGH DETAIL FROSTED acrylic, because the cheap stuff didn't come out as well.

We are going to have the pendant cast in metal next, and then we'll see how well the prongs actually work.

i don't know about pearls, sorry cant help you there.