Rare Earth Elements
Rare Earth Element is a term often used to denote the following metals:
The Actinides are included in some defenitions.
"Earth" is an obsolete term for "oxide", and is translated from the french word "terre" which was the international language at the time these metals were discovered. They are, in fact, not rare elements (excluding synthetics) and are quite abundant in earth's crust.
This term has now been depreciated by the International Union of Pure and Applied Chemistry.