Boron-rich molecules and solids hold a special place within chemistry. They do not follow the general bonding rules we are taught in chemistry classes. For example, some boron-rich solids are composed of 12-atom clusters of boron atoms in which each boron atom resides on a vertex of an icosahedron. These solids are very stable refractory materials with melting temperatures up to 2400 °C—a thousand degrees greater than silicon's. Beyond this, they possess numerous novel structural, electronic and thermal properties that are not only interesting but useful.