osmium: a hard brittle blue-grey or blue-black metallic element that is one of the platinum metals; the heaviest metal known
metallic element: any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.
keratoacanthoma: skin tumor that grows rapidly (especially in older people) and resembles a carcinoma but does not spread; it usually disappears spontaneously, often leaving a scar