The remarkable appearance and consistency of chocolate are a direct expression of the physical qualities of cocoa butter, the part of chocolate that surrounds the solid particles of cacao bean and holds them together. When carefully prepared, chocolate has a silken or glassy surface, is hard and not greasy at room temperature, breaks with a delightful snap, yet melts to a smooth creaminess in the mouth. These are very unlike the qualities of any other food, and are a consequence of the structure of cacao fat molecules, which are mostly saturated and unusually regular (most of them are constructed from just three kinds of fatty acids). This structure means that the fat molecules are capable of forming a dense network of compact, stable crystals, with little liquid fat left over to ooze out between the crystals.