roepperite
/ˈrəːpərʌɪt/Mineralogy. Now disused
noun
A black mineral of the olivine group containing manganese and zinc, now identified with varieties of fayalite or tephroite.
- The chemical formula assigned to the mineral was (Fe,Mn,Zn)2SiO4..
Origin
Late 19th century. From the name of William T. Roepper, German-born U.S. mineralogist + -ite.