Hey, guys.......
There's sure to be a store that sells jewellery in your area..........
They MUST have an idea where jewelerry can be repaired, and THEY can tell you where to get jewellery supplies.
The thing that sailordave is talking about is kinda like a hinged clothes peg - but it has a little wedge in the back side that forces the frontside closed (onto the item to be clamped).
Easy.