Dysprosium
Properties
| Atomic Number | 66 |
| CAS Registry Number | 7429-91-6 |
| Chemical Symbol | Dy |
History
The atomic number is 66 and the chemical symbol is Dy. The name derives from the Greek dysprositos for hard to get at due to the difficulty in separating this rare earth element from a holmium mineral in which it was found. Discovery was first claimed by the Swiss chemist Marc Delafontaine in the mineral samarskite in 1878 and he called it philippia. Philippia was subsequently found to be a mixture of terbium and erbium. Dysprosium was later discovered in a holmium sample by the French chemist Paul-Emile Lecoq de Boisbaudron in 1886 who was then credited with the discovery. It was first isolated by the French chemist George Urbain in 1906.Holden, Norman E., (2004). History of the origin of the chemical elements and their discoverers. National Nuclear Data Center. Retrieved from http://www.nndc.bnl.gov/content/elements.html