The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook American Heritage Coll.
Solid gallium is a blue-gray metal with orthorhombic crystalline structure.
The liquid metal has a beautiful silver color. Although gallium is solid at normal room temperatures, it becomes liquid when heated slightly. It is the only metal other than mercury, cesium, and rubidium that has this property. The metal is relatively unreactive. It is used to form low-melting alloys.