The process of gas transforming into solid is known as deposition or desublimation, which is the reverse process of sublimation.
A good example of illustrating depositation is the process by which, at temperatures below freezing, water vapor changes directly to ice without first becoming a liquid. This is how snow forms in clouds , as well as frost and hoar frost on the ground. Also an example may be considered when frost forms on a leaf. For deposition to occur, thermal energy must be removed from a gas. Only when the leaf is getting cold enough, the water vapor in the air nearby the leaf loses enough thermal energy to change into a solid. Depositation in water occurs due to the pureness of the water vapor. Given the fact that the vapor has no unknown particles, it is able to lose big quantities of energy before forming around something. At the moment the leaf is being introduced, the cold water vapor immediately starts to condensate, this thing causing the direct change of the water vapor into a solid. Another example is the artificial process of physical vapor deposition, used to deposit thin films of various materials onto various surfaces.