Carbon dioxide (dry ice) sublimes directly from a solid into a gas, as does crystalline Iodine. In fact, if the temperature never rises above the freezing point, water in the form of ice, will also sublime and eventually an ice cube, left alone in a freezer will ‘disappear’. The opposite of sublimation is ‘deposition’ which refers to the transformation of a gas directly into a solid without becoming a liquid. It’s pretty rare in nature, but when ice crystals form on your window, even when it isn’t raining or snowing, that’s deposition (or when a lawyer takes your testimony – that’s truly cold!!).