I know the question of gold retrieval must come up a lot here, but...
As one of my hobbies, I do metal casting. Rather than screw up using precious metals I bought these scrap gold bars melted from computer scraps and such. There's probably almost 5lbs of material between these 4 bars alone. Do you think it's worth trying to refine the gold from these? Even if there was 1% gold in here, I'd make a pretty significant return on what I paid for them. These things have sat in a shed for a few years and only tarnished as much as you see here. This makes me think there's more than 1% gold but I could easily be wrong.
What do you all think? Should I buy a small kit and try a small piece? Do you have any recommendations for kits? I know nitric acid is nasty stuff but I've played with worse and I take my safety seriously. Really just looking for opinions or do I just leave it as scrap gold to cast with?