Pearls with mysterious mark JOM

by Adriana
(Bastrop,Texas, USA)

I recently was given a pearl necklace by my deceased grandmother. I have been trying to find out more about it just out of curiosity. It has a 14 karat yellow gold clasp with white/silver pearls that are not perfectly round. It is also stamped JOM.

Anything about it would be great! I have only found one other piece like it and it was a black baroque bracelet from an estate sale.