penroseite
/ˈpɛnrəʊzʌɪt/Mineralogy
noun
A rare grey mineral of the cubic crystal system which consists of nickel selenide, NiSe2 (usually with some cobalt and copper), and occurs as reniform masses.
Origin
1920s. From the name of Richard A. Penrose, Jr., U.S. mining geologist + -ite.