Some would call this a faux moon glow stone. I believe it is a thermal plastic they used in the late 50's early 60's. It is a deep red and will compliment any French cuff or blouse. Overall size of cufflink is 5/8" x ¾" with tie bar 1 ¾" in length. Both men and women could wear this set. It is in very good condition with no maker's mark. There is a tie clip that matches but I don't necessarily think this tie clasp was the original. It will be thrown in for free if you would like it also.