‘A Signet Ring’

This is a Signet Ring bearing the Coat of Arms of the original Alleyns School, before it and Dulwich College, where my father was later a pupil, became separate schools. It was worn by my grandfather, who I never knew, who taught there as a young man in the late 1800s - well over a hundred years ago!
I have no idea if it was ever used as a stamp though!

More details here