Bar pin probably gold plated or gold filled, with multiple sections, each with different designs cut or engraved into them. In some sections, black enamel fills the designs, a technique called taille d'épargne. Much of this is worn off. In the center compartment there is a crescent moon and a rose cut stone, glass, garnet or ruby? There is a tube hinge and a c clasp shaped like a hood. 1 11/16" long 7/16 wide