What is a precious stone of any kind, as the ruby, emerald, topaz, sapphire, beryl, spinel, etc., especially when cut and polished for ornament; a jewel. Milton called?

gem — A precious stone of any kind, as the ruby, emerald, topaz, sapphire, beryl, spinel, etc., especially when cut and polished for ornament; a jewel. Milton. (Webster's 1913.)