metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

fergusonite - a dark mineral consisting of oxides of yttrium and erbium and tantalum and other minerals

gadolinite, ytterbite - a mineral that is a source of rare earths; consists of silicates of iron and beryllium and cerium and yttrium and erbium