Kryptonite ring

A Kryptonite ring is a ring that is made out of Kryptonite. Wealthy industrialist Lex Luthor acquired a small piece of Green kryptonite and had it fashioned into a ring. This was his means of not only taunting Superman, but also to Superman from manhandling him. After a while, Lex developed kryptonite poisoning from the ring, and had to have his hand amputated.