Americium is an actinide that has a silvery white, or yellow, color in its natural solid state. It tarnishes in dry air, and it is somewhat malleable. Americium has an atomic weight of 243, a melting point of 2149 °F, and a boiling point of 4725 °F. Americium does not have many commercial uses as it is very expensive to produce. Americium is used in minute quantities in some smoke detectors, in the production of certain types of glasses, and as a source of ionizing radiation.