Fergusonite, named after Robert Ferguson, is a mineral of a brownish black colour, essentially a tantalo- niobate of yttrium, erbium, and cerium. Research Fergusonite
Gadolinite, named after the Russian chemist Gadolin, or ytterbite is a naturally occurring complex silicate containing beryllium, iron and many of the rare earth metals, of which the latter is an important source. The principal rare earths that occur in gadolinite are yttrium and erbium, together with smaller amounts of cerium and lanthanum.It is usually found in dull, amorphous masses disseminated through granite; is black, or very dark green in colour, with a resinouslustre. *Gahnite
Gahnite (zinc spinel) is a dark green mineral of the spinel group consisting of zincaluminiumoxide. It is named after J G Gahn the Swedish chemist. Research Gadolinite
Abbreviations
Research Erbium
