Likely carved out of shell. Oval pin depicts Euterpe, the muse of music, one of the nine daughters of Zeus and Mnemosyne who presides over the arts and sciences and is the source of creative inspiration. She is playing an aulos, a type of double flute played in ancient Greece. It is finely carved. The setting is probably sterling but not marked. Hinged loop can make it into a pendant. Tube hinge and safety c clasp. 1" tall. 7/8" wide