A few months ago I found what I believe was an old uninterruptable power supply from 1994 (the year was printed on the inside of the case). Inside it was a lot of beautiful metal. Lots of copper, but also a heat sink which weighs a few pounds and is black. I'm not sure what type of metal it is, although I have a suspicion that it's probably anodized aluminum. It feels heavy for its size, but I can't imagine something that big being pure copper. Is there a way I can tell what it is? I don't have a scale so I can't weigh it.