Hörnesite

Hörnesite
General
CategoryArsenate minerals
FormulaMg3(AsO4)2·8H2O
Strunz classification8.CE.40
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupC2/m
Unit cella = 10.262, b = 13.442
c = 4.741 [Å]; β = 104.9°; Z = 2
Identification
References

Hörnesite is an arsenate mineral bearing magnesium. It is a member of the vivianite group of minerals, and constitutes the magnesium endpoint of a mineral series with nickel or cobalt replacing the magnesium, ending in annabergite or Erythrite.