Cleaning silver / opal earrings

Any suggestions on how to clean these?

These earrings were purchased in Mexico back in the 1950s. Tarnished silver with opals. What would be the best way to clean them? Would solution of baking soda / salt on aluminum foil damage the opals?

I can't seem to get that duplicate image out of the post. Oh well. So be it.

:o

Unless they are solid or sterling silver I would be very, very careful Marie as the gems may be worth more than the setting. I can't actually read the mark on the back and as one is very faint I would suggest silver metal is the setting.

Gill, I couldn't make out the mark on reverse either. Thanks for responding.

I'm not sure what the stones would be worth. When I looked at the earring to begin with, they looked bronze because of the tarnish. The other thing that I could do is change out the old screw backs for bronze french hooks. Maybe clean tarnish just off the back of the setting.

Be very careful as opals are easily damaged.

Probably worth getting the advice of an actual jeweller. It can't hurt to ask one and I've never found them unwilling to give free advice.

Thanks everyone. :)