jamesonite
noun
jame·son·ite
ˈjām(p)səˌnīt,
-məs-
plural -s
: a gray orthorhombic mineral Pb4FeSb6S14 consisting of a lead antimony iron sulfide, having a metallic luster, and occurring in fibrous masses
Word History
Etymology
Robert Jameson †1854 Scottish mineralogist + English -ite