My immediate impression was MOP, so glad to see that was confirmed. I'd be very leery of using ultrasound on them but have no direct experience.
Wow. You’re back. I’m so happy! I checked a site when searching for the right solutions to buy and they gave a list of things not to ultrasound and mother of Pearl was on it as not.
The solution of hydrogen peroxide and baking soda didn't touch this last bit of nicotine in the crevice between the MOP and the silver, but thank you anyway @Hollyblue for your possible solution. A reseller suggested LA Totally Awesome. I'll try that next.
Thank you, Kiko. Trying to catch up. Surprised at the number of cameo related inquiries came in during my absence. Wouldn't you know.
Your carved MOP earrings are gorgeous. I've used acetone to clean carved MOP buttons (photo below) and wonder if the remaining yellowish stuff on your earrings is darkened glue residue. If the earrings were mine, I'd tightly twist the corner of a kleenex/tissue and dip it in acetone (or nail polish remover), then use the tip of a wooden toothpick to push it along a tiny section of the MOP edge and see if the yellow starts to disappear. If so, it's probably glue. Using too much solvent could loosen the stone, but I might even soak the whole front of the earring in acetone to see if the stone comes out completely, then give it a good clean with acetone, including any glue residue on the silver setting under the stone, then re-glue it with G-S Hypo Cement. Acetone doesn't damage silver, but if it has a lacquer coating, it will dissolve. Disclaimer: I've been known to ruin jewelry by trying to "fix" problems, so proceed with caution if you decide to try this, and be sure to have good ventilation or wear a mask.
Joan. So glad you happened along my post. I treasure your actual experience with cleaning MOP. This is most helpful. I'm sure the original grime was nicotine. My mother smoked unfiltered camels and and the nicotine yellowed every surface. I think you're right, it is glue. I will try the acetone, but I appreciate the idea of the Simichrome coating. Thank you very much! Kiko
Thank you, Kiko. I just used the Simichrome on a cloth to polish the MOP after the acetone, then buffed it with a clean soft cloth to remove any excess Simichrome. I hope it works, and would like to see an "after" photo.