Many times a two tone gold ring is Rhodium plated to make the
recessed areas white gold appearing. Careful re-polishing the higher
places will give the piece a two metal look. It can still be stamped
14 Kt even though there is a two colored look. This lasts quite a
while if the plated areas are recessed and not an area receiving a
lot of wear. If you see any old “Swiss Cut” jewelry, and see two tone
it is just plated most of the time.
Having done quite a bit of plating in the past, (more
electroforming) my experience is primarily plating pure silver not
sterling. I’m not even sure if they make a sterling silver plating
solution. Someone with more experience can comment here. Pure silver
does not antique well. Same as pure jewelry made of silver doesn’t
antique very well.
In the old days there used to be an black antiquing product called
Jet Black. This was a cyanide based antique you would burn on. Almost
passed out using it in an unvented area once. Nasty stuff. It was
very black and stuck on both white and yellow gold beautifully. Most
cyanide is gone from our jewelry world now days. Not much will stain
gold that I know of. Plate yes, burn on no. I’ve tried all the
antiques that are applied with the steel applicator and am not
satisfied at all.
Don’t think plating silver on gold to antique will work.
Old school is good school,