Because of its magnetic properties,
holmium has been used to create the strongest artificially-generated magnetic fields when placed within high-strength magnets as a magnetic pole piece (also called a magnetic flux concentrator). Since it can absorb nuclear fission-bred neutrons, the element is also used in nuclear control rods. Other commercial applications of the element abound:
- It is used in yttrium-iron-garnet (YIG) and yttrium-lanthanum-fluoride (YLF) solid state lasers found in microwave equipment (which are in turn found in a variety of medical and dental settings).
- It is used as a yellow or red glass coloring.
- Holmium-containing glass has been used as a calibration standard for UV/visible spectrophotometers
- Holmium is one of the colorants used for cubic zirconia for use in jewelry, providing a dichroic color in peach or yellow, depending on the lighting source.
- Holmium may be used as the active ion in some solid state lasers.
- The radioactive but long-lived Ho-166m1 is used in calibration of gamma ray spectrometers.