The 'black ice' from Faldage's link bothered me as a problem a year ago and still bothers me. It is a most excellent word--descriptive, accurate in terms of what to avoid, and malevolent-sounding enough to strike us with a serious warning. Anyone who has traveled down winding country roads on freezing mornings who has been warned about black ice must be grateful for such a term because as the headlights illuminate the dark road and that glistening shining patch of patent-leather appearing ice comes into sight, one thinks: Black ice! And will slow down even more to avoid the deadly consequences of not doing so. I know of too many paraplegic, quadraplegic, and death episodes to think of that ice as anything but black ice.