franckeite
noun
franck·e·ite
ˈfräŋkəˌīt
plural -s
: a mineral consisting of a dark gray or black massive lead antimony tin sulfide (specific gravity 5.55)
Word History
Etymology
German franckeït, from Carl and Ernest Francke, 19th century German mining engineers + German -it -ite
First Known Use
1893, in the meaning defined above