Sublimation can be used for separating substances, which can sublime - transform from solid phase directly to gaseous phase by heating (or by cooling down vice versa from gas to solid), skipping the liquid phase. One of those substance is iodine (I2).
In this experiment, sublimation is used to separate iodine from a mixture with sand. The mixture was heated in a beaker. Iodine evaporated (reddish-violet gas upon heated mixture), but the sand did not. Upon contact with cold flask surface, the iodine vapor turned again into brownish gray crystals of iodine.