How Do I Clean Discolouration Near the Clasp of Deltah Pearl Necklace

by Gloria
(California)

Hi-

I have a 3 strand Deltah pearl necklace with rhinestone clasp from the 1930s that I want to sell.

Before I do that, I'd like to clean up the discoloration (if possible) on the metal near the clasp. There's also some discoloration (greenish hue) on the pearls closest to the clasp (about 3 pearls on each side).

I have already brushed the area gently with a soft toothbrush (as suggested elsewhere online) and got rid of some of the green junk. But some discoloration remains.

The pearls themselves are in good shape and have been stored for decades in their original pink Deltah box.

Any suggestions on what to do would be welcome.

Thanks.

Gloria