Does anyone know how to render flat metallic gold properly?

Hi there,
I struggling to render a flat gold pendant on pure white background (no background in fact).
I’ve been trying for days now and the result just sucks.
The color of the gold is wrong.
The highlights are too shiny on the outer sides of the piece, so it blends with the white environment.
I notice on professional renders (which I untderstand are retouched with Photoshop), the reflections on the outer side of the pieces or chains are black, to create separation with the white environment.
I’ve tried all the environments in Rhino7, rotating them all, and I cannot create that effect.
I’ve tried surrounding the piece with a dark reflector, but it’s not satisfactory either.
So many things I don’t understand (why is there still light even if I turn off the sun??)
Is there anyone on the forum who is experienced enough in that field to point me in the right direction?
Thanks in advance

You already asked before: Can I install rhinopbrmaterial in Rhino 7? (or is it already included?)

The answer will be the same. You can pick any environment (see for instance that gives you the reflections you need, then do postprocessing in Photoshop/GIMP.

Anyway, see the post I linked in the previous topic.