Gold plating with soft stones

I am making a piece with stones I am told by the plater are too soft
to undergo the process–they’ll lose their luster. I was going to set
them after plating, but now I’m afraid I’ll rub off the gold when I
do. Would it work if I first coated them with clear nail varnish &
then removed the polish after plating?

I would use a proper stopper such as lacomit rather than nail
varnish. The hardness will not make a difference to the lustre after
plating but many of the softer stones will be attacked by the acid in
the electrolyes of the plating baths.

Nick royall

If the plater uses the cyanide process then no problem with soft
stones like pearls, lapis, and opals. If they use an acid process
then soft stones are a problem.

The cyanide process is becoming more rare because of the endemic
fear of terrorism and the psudo guarantee of safety for all. Cyanide
does exist but it’s harder to do nowadays. Cyanide is dangerous and
the safety measures are well known since the 1900’s.