Vintage Phi Eta Kappa Fraternity Pin w/Guard

As we clean out my mother in law's home of over 60 years we found this.

This is my father in law's college fraternity pin from the Univ. of Maine Orono, class of 1943. He belonged to Phi Eta Kappa. I strongly suspect this is gold but is not marked as such. On the back bears the intials JPC 43

the skull & cross bones are featured on the front of the main pin. The pin shield is surrounded by seed pearls faux I'm not sure- and the skull has some sort of green stone eyes.