What is Dysprosium?

As a member of the heavy-group rare-earth elements (HREE), dysprosium has two paired electrons giving it the ability to detect radiation, improve permanent magnets, store digital data, precisely aim lasers, emit sonar pings, or glow in the dark.


  • Atomic Symbol: Dy
  • Atomic Number: 66
  • Element Category: Lanthanide metal
  • Atomic Weight: 162.50


It is used in the following applications:

  • Dysprosium in Terfenol-D, is used to produce sonar sensors, positioning actuators, active noise and vibration cancellation, seismic waves, and tool machining.
  • Dysprosium phosphide (DyP) is a semiconductor used in laser diodes and high power, high-frequency applications.
  • A dysprosium additive to neodymium-iron-boron magnets increases the operating temperature range for use in hybrid and electric vehicles.
  • Dysprosium oxide in a cermet is used in nuclear reactor control rods to control the fission process.
  • Dysprosium-165 is injected into joints in the body to treat rheumatoid arthritis.
  • Radiation badges to detect and monitor radiation exposure.
  • Coating compact disks (CD) for digital data, music, and video storage.


Dysprosium was discovered by French chemist Paul Émile Lecoq de Boisbaudran in 1886. Working with an impure holmia, Lecoq de Boisbaudran used fractional crystallisation to separate the impure holmia using ammonium hydroxide, followed by additional separations using potassium sulfate. After multiple fractionations, four “earths” precipitated in the following order: terbium, dysprosium, holmium, and erbium. Three of the elements had previously been discovered. In discovering dysprosium, Lecoq de Boisbaudran noted that he had very little material to work with and confided in Professor Georges Urbain that most of his fractional crystallisations had been prepared on a marble fireplace slab at his residence in Cognac, France. Dysprosium is named after the Greek word, dusprositos (δυσπροσιτός), meaning difficult to approach or get at, in reference to the painstaking number of fractional crystallisations needed to make the precipitate.


Large resources of dysprosium in xenotime and monazite are available worldwide in ancient and recent placer deposits, uranium ores, and weathered clay deposits (ion-adsorption ore). It occurs in the Earth’s crust at an average concentration of 3 parts per million(ppm). Xenotime is enriched in dysprosium oxide and contains 8% to 9% of the rare-earth oxide (REO) content. Monazite-(Ce), which is more abundant in the Earth’s’ crust than xenotime, has dysprosium oxide contents of 0.2% to 0.9% of the REO content.

Hastings’ Yangibana Project contains an average of around 50ppm Dy2O3, which is higher than the average concentration in the earth’s crust.