Indium is amazing metal. It bonds strongly to glass (i.e., it can "wet" glass) and is transparent. Thus, Indium is used to give a mirror finish to windows of tall buildings (Indium is as reflective as silver, but Indium window finishes don't tarnish as quickly as does silver), industries to make Indium Tin Oxide (IT)). ITO is transparent, so that it becomes a transparent electrode - which is used touch screens, flatscreen TVs and solar panels.Because it has a low melting point, it is used for fire-sprinkler systems. Most interestingly, when you bend Indium, it cries (producing a cracking sound) as the crystal atomic lattice structure is torn and reformed.