Is pure iron water-soluble

Notes for schools: Due to the high reactivity of the powder, only crushed chunks of the pyrite should be stored and used for roasting experiments.


Iron (II) disulphide forms shiny golden yellow crystals which crystallize according to the cubic system. They are insoluble in water. The substance is attacked in powdered form by acids or by moist air. The powder can ignite spontaneously with atmospheric humidity or thermally explosively decompose. This danger exists especially in the case of contamination with flammable substances. In contrast to iron (II) sulfide, compact pieces are relatively stable. When compact pieces hit a flint, sparks are produced with a smell of sulfur. When heated strongly in air, iron (II) disulphide converts from 800 ° C into iron (III) oxide and sulfur dioxide.

4 FeS2 + 11 O2 2 feet2O3 + 8 SUN2   

Crushed pyrite as a natural raw material for the production of sulfuric acid