Tin is a chemical element with the symbol Sn and atomic number 50. Tin is a silvery metal that characteristically has a faint yellow hue. Tin, like indium, is soft enough to be cut without much force. When a bar of tin is bent, the so-called tin cry can be heard as a result of sliding tin crystals reforming; this trait is shared by indium, cadmium, and frozen mercury. Pure tin after solidifying keeps a mirror-like appearance similar to most metals. However, in most tin alloys, the metal solidifies with a dull gray colour. Tin is a post-transition metal in group 14 of the periodic table of elements. It is obtained chiefly from the mineral cassiterite, which contains stannic oxide, SnO2.