Rhodium Plating for .925 Silver

Can you tell me what would be the appropriate micron thickness for plating a .925 Sterling nickel-free item?

What would be a reasonable cost to expect to plate one piece that is a pendant approximately 5 cm by 8 cm?

What should I ask a jeweler to determine if he is reputable for doing plating on my item?

Thank you in advance for your help.

Hi Eileen,
A pendant finish will not have to endure the same wear as a wedding band. Rings should be plated with a minimum of .25 -.50 microns. If you want the pendant to last ask the jeweler to plate .50 micron in rhodium. Rhodium prices have gone through the roof lately. Without masking or anything else that would be labor intensive, you should be able to have the pendant plated for $125.00 - $150.00 at the aforementioned thickness.
Most jewelry chain stores don't plate rhodium, they send it out to be plated. The store does not have very much control in this case. You can seek out a privately owned jewelry store that designs and handcrafts the jewelry that they sell. They are more likely to give you exactly what you want, and many of these stores plate the rhodium in house. Ask the jeweler if they can certify the rhodium thickness after plating to make sure you are getting what you pay for. Good Luck!