ˈfərgəsəˌnīt noun
( -s )
Etymology: Robert Ferguson died 1865 Scottish physician + English -ite
: a brownish black mineral (Y,Er,Ce,Fe,)(Nb,Ta,Ti)O 4 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)