Jamesonite
Pronunciation : Ja"me*son*ite
Part of Speech : n.
Etymology : [From Prof. Jameson, of Edinburgh.] (Min.)
Definition : Defn: A steel-gray mineral, of metallic luster, commonly fibrous massive. It is a sulphide of antimony and lead, with a little iron.
Source : Webster's Unabridged Dictionary, 1913