fergusonite

noun

fer·​gu·​son·​ite

ˈfərgəsəˌnīt

plural -s

: a brownish black mineral (Y,Er,Ce,Fe,)(Nb,Ta,Ti)O₄ consisting essentially of an oxide of yttrium, erbium, niobium, and tantalum with other metals often including uranium and isomorphous with formanite (hardness 5.5–6)

Word History

Etymology

Robert Ferguson †1865 Scottish physician + English -ite

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