1) Sulfide mineral 
Djerfisherite is an alkali copper–iron sulfide mineral and a member of the djerfisherite group. It has the chemical formula K6Na(Fe2+,Cu,Ni)25S26Cl. Its type locality is the Kota-Kota meteorite (Marimba meteorite), Malawi. It was first described in 1966 and named after professor Daniel Jerome Fisher (1896–1988), University of Chicago. It has b...