OK, odd story. I got ahold of an old exterior light fixture that was being tossed out. I immediately saw what looked like an aluminum shade around the bulb itself and it was a metal fixture so I grab it. Take it apart, there's a transformer inside (it was a big sodium bulb style old school exterior fixture for a small barn) Unfortunately transformer was all Aluminum wires for wrap , no copper. The body of the thing was a grayish metal, I figure it to be some style of Pot Metal. I bash it up with a hammer into small pieces (it breaks easily, doesn't bend). I'm doing a melt of some aluminum I picked up, and afterwards decided to test this mystery metal. Put in a small piece in a crucible I had just emptied and scraped of aluminum. It melts pretty fast, no white fumes/smoke (so no Zinc I guess). The metal was a dull medium gray, so I figured it wasn't aluminum. I then melt the rest of the housing and pour into an ingot mold. Now, I'm used to the fact that as Aluminum cools it will often form a depression on the top as the center cools and everything compacts. It's cavitation from what I've read and normal to expect Aluminum to do this, less so though on some other metals like copper. I pour the mystery metal and no cavitation at all, top of the ingot stayed nice and flat as it cooled. But it pours with a silvery brightness right there will the aluminum I poured a few seconds ago?? Safe to just call it Monkey Metal and call it a day? Are there better methods you guys use for easily identifying the non-ferrous stuff we pick up and play with beyond "melt a little and find out!"??