Tuttons
Tutton's salts are a class of double sulfate salts consisting of ammonium and a divalent metal cation. The general formula is (NH4)2[M(SO4)2]·6H2O, where M2+ is a divalent metal such as Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, or Mg2+. These salts crystallize from aqueous solution as hexahydrates and often show isomorphism across different metals.
The physical properties of Tutton's salts depend on the metal ion. The crystals are typically color influenced
Preparation usually involves crystallization from an aqueous solution containing both ammonium sulfate and a soluble metal
History and nomenclature reflect the work of a 19th–early 20th century chemist after whom the compounds are