I have been playing with some exotic filaments lately. Here are three 3DBenchy boats printed with metal filaments.
PLA-Copper, PLA-Brass, ABS-Tungsten

I need to play with my settings a bit on the Copper and Brass but the Tungsten turned out really nice. I upgraded my extrudes with the Micro Swiss all metal hot ends. I have my left extruder setup with a 0.6mm nozzle and the right is 0.4mm. The copper was printed with the 0.4mm, the brass and tungsten with 0.6mm. The brass is weird stuff, it seems more liquid than the others and just poops out of the nozzle. I've tried messing around with different temperatures but I've found it is just difficult to print with.

I am now trying to polish these with a rock polisher/tumbler.