Iron(II) sulfide

Chemical compound

Iron(II) sulfide

Iron(II) sulfide or ferrous sulfide (Br.E. sulphide) is one of a family of chemical compounds and minerals with the approximate formula FeS. Iron sulfides are often iron-deficient non-stoichiometric. All are black, water-insoluble solids.

From Wikipedia, under CC BY-SA. More on occurri.