I just tried making a metal>gold material and apply it to the watergun I was using to test Artic viewmodes. And THsi is what I see on the viewport:
and when I render I get nada:
and raytraced viewport:
I made this scene by going to File>New>Small Millimeters and pastig the modle there. 3dm file attached.
black_gold_watergun.3dm (2.0 MB)