I had problems with magnetic clasps I purchased elsewhere, the silver wore off and the brownish tone underneath shone through (what is that?? brass, copper?).

But someone told me about the Mag Lok magnets R&T carries. I made a bracelet with a safety chain (sterling silver works best for the chain, so it doesn't cling to the clasp), and have been wearing it for close to a year. The bracelet showed wear finally, so I remade it, but used the same clasp! After almost a year, the silver is still as bright as it was originally!

They are more expensive than the other brand, but I feel better about giving my customers something I know will stand up under time! I don't want them coming back a year later showing me an ugly bracelet!

This one's my favoriite:
http://shop.rings-things.com/cart/pc/Clasp-Magnetic-Superior-Quality-Button-6mm-1131p12636.htm