| Dysprosium (also known as demonium) is one of the least abundant of the rare earth elements. Its salts were isolated in a pure state by Urbain in 1906. They are yellow or greenish-yellow in colour. |
| In 1843, Swedish chemist Carl Gustav Mosander separated yttria into several earths, one of which kept the original name. On the second half of 19th century 11 rare earths had been extracted from yttria. The last new earth was impure too and split by Francois Lecoq de Boisbaudran in 1886 into holmia and a new oxide, which he named dysprosia, derived from the Greek dysprositos = hard to obtain, because of the difficulty involved in its detection and isolation. In 1906 Georges Urbain recovered pure dysprosium. |
| Lanthanide Dysprosium crustal abundance is 5x10-4 mass %, in sea water 7.3x10-7 mg/L. As other rare earth elements it is contained in many minerals, including gadolinite, xenotime, and in less amounts in monazite, bastnasite and apatite. |
| Calcium, sodium or litium DyCl3 or DyF3, reduction. |