Fergusonite

n.

1.

(Min.) A mineral of a brownish black color, essentially a tantalo-niobate of yttrium, erbium, and cerium; - so called after Robert Ferguson.

Noun

1.

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

atomic number 39, atomic number 68, atomic number 73, Er, erbium, mineral, Ta, tantalum, Y, yttrium