Jarosite
Chemistry: KFe3(SO4)2(OH)6, Potassium Iron Sulfate Hydroxide.
Class: Sulfates
Group: Alunite
Uses: Only as mineral specimens.
Specimens
Jarosite is not a common mineral. It is closely related to the mineral natrojarosite. Jarosite is isostructural with natrojarosite which means that they have the same crystal structure but different chemistries. In this case, jarosite contains potassium instead of natrojarosite's sodium (natro is derived from the Latin for sodium, natrium, from where sodium gets its symbol, Na). The two minerals are difficult to distinguish without a chemical test.
