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.