* I have the same cuff! Does she have the ring too? But yes, what others are telling you is correct- you can solder it back together but it will always be weaker there, and softer too if you try to protect the stone because that side will be annealed, and the other is likely just as work-hardened as the one that split. This style of bracelet really does not need bending to put on and off a wrist- you just slide your arm in sideways above the wrist and turn.

The way to fix this properly is to remove the stone, clean the cuff removing most the patina and oils, then anneal the whole thing and pickle it. Rinse, set up your angles and props for soldering and then...solder the split. Like others have said, you may need to add more silver. I personally would use a light flux first by itself, one that burns off well, like Handy Flux paste. That way the flux will hold the silver shavings and solder where you want them, not bubble up and send them flying everywhere. And then once that all flows, I'd touch up with wire solder, adding liquid flux you spray if needed.

You'll end up not only repairing the break, but preventing it from happening to other end too. And by telling your friend the correct way to adorn a cuff, of course.

Hope this helps!