Holmium is a rare earth metal that is silvery-white in color, and very soft and malleable. It is a highly magnetic metal, with a magnetic field that is about 5 times stronger than that of iron. Holmium has a number of uses, including as a component in nuclear control rods in nuclear reactors, as a colorant in glass and ceramic materials, and as a dopant in solid-state lasers. It is also used in the production of specialized magnets, such as those used in MRI machines.