She can buy a type of metal called magitite, which is essentially a lightning rod as far as materials go. It draws magic towards itself and pulls it in, much like regular metal pulls things like electricity. Crafting it to use that magic afterwards is more difficult, however, and requires more specific magical knowledge of magic weapons crafting that Peridot might have at the moment.

Of course, Brauni is willing to show her how to work with it for an extra fee if Peridot is interested. It would be about 300 for one bar of magitite and some lessons from her to show how to create some kind of release function.

How much magic it can store is going to be limited to the size of the piece... but as you can guess, a full set of armor made of this stuff would be extremely potent.