Baroque pearl discoloration

by Margret
(Nashville, TN)

Hello,

I purchased a lovely pair of white baroque pearl earrings last spring from a reputable NYC jeweler. They have 14K (I believe) posts and larger gold backs to help them stay up on the ear lobe.

Tonight I was looking at them and noticed that - on one more than the other - the bottom near the pist attachment was almost a chalky white. The base has lost its luster and almost appears plastic like. The area of discoloration is not uniform, but I believe you could see the edge of it with the earring on.

What would cause this? I've only worn them twice and they have been kept in my velvet lined jewelry box. I'm certain that I would have noticed this if it was there when I purchased them. I am fairly particular.

Before I call the store and send them to them, I wanted to get your thoughts.

Thank you in advance for your help.