Broken costume jewelry sorting

As an antique dealer/auctioneer I end up with lots of busted up jewelry and things like pin backs when buying in bulk. The steps are usually

1. You comb through and find the good stuff to sell by the piece,
2. get the not so great stuff to sell again in another lot
3. Collect the pieces you can repair easily and repeat steps 1 and 2
4. Set aside the pieces you can't repair easily or aren't worth repairing and sell it in bulk lots on ebay
5. Wonder what to do with all the leftover metal if you can't shove it into an ebay repair lot.

It does happen sometimes where you just end up with a pile of metal stuff you never got around to. Shoving it into the bulk lots on Ebay kind of works but they like pieces with actual settings & rhinestones to work with and if you have just a bunch of nonsense taking up half of the weight you will get much less money then if you just didn't put it in. Guess people just don't want a big heap of trash to deal with.

Anyway the pile I have now is just a few pounds and already free of precious metals. My question is, is there a quick way to scan for nickel or whatever would bring more than $250/ton? Even if there is only hardly a pound, it would be just something else to look for when I'm scanning for bits of silver and gold.

EDIT:

Using a magnet there are some that are absolutely not magnetic, some that are a little bit, and some that fly to the magnet.

EDIT AGAIN:

These links are kind of cool. Didn't think I would find anything like this. The second one is big and takes awhile to load:

http://www.ccmetal.com/about.php?panel=1
http://www.ccmetal.com/catalogs/jewelry-findings.pdf