2 metals. Mix material, dirt shader to distribute them, nothing too fancy. Gold portion is a universal material with GGX BRDF model.
Very quick attempts at 3d print material. This still needs work.
I've been experimenting with some of the newer material modes in Octane, so decided to test some out using models by the talented Mia Kay: https://www.thingiverse.com/M3DM/about https://www.artstation.com/m3dmprints