A month or so ago, I was given the opportunity to raid a pile of to-be-discarded computer parts. I went to it vigorously! I built a computer with some parts, FINALLY got DVD drives with stepper motors for my laser cutter, and stole every single stick of RAM in the pile. Why did I commit this heinous act of villany? Gold! (Also, the parts were being thrown out, so without my intervention, all the parts would have gone to some recycling corporation. Not techy, DIY or scientific.) On every stick of RAM, there is a little bit of gold in the contacts. Gold is necessary for this application instead of copper because copper oxidizes and tarnishes in air, creating a layer of unconductive compounds. This will severly hamper the job of an electrical contact. To recover the gold, I used sheet metal benders to break off all of the contacts while taking nothing else. Then, I put them in a bath of copper etchant to remove the copper backing on the gold. I used NurdRage's 10:1 ratio of 3% hydrogen peroxide to 96% sulfuric acid.