Chemical matt finish for Gold?

Hello!

Maybe anyone can advise me a better way to create chemical
consistency that can make yellow and white gold - 14 and 18 carat
matt. i’m interested in acids’ names and proportions.

Thank you,
Olga, Saint Petersburg
Russia

I know you asked about a chemical method, but have you considered a
mechanical method? Bead blasting, with fine glass beads, produces a
beautiful, consistent matt finish on all precious metals. Just a
thought.

Regards, Gary Wooding