The element that is in all sulfides and sulfates is sulfur (S).

* Sulfides are compounds where sulfur is bonded to one or more metals. Examples include iron sulfide (FeS) and lead sulfide (PbS).

* Sulfates are compounds where sulfur is bonded to four oxygen atoms, forming a sulfate ion (SO₄²⁻). These ions then bond to various metals or other cations. Examples include calcium sulfate (CaSO₄) and sodium sulfate (Na₂SO₄).