Ruizite

Ruizite
Clusters of ruizite on calcite from South Africa
General
CategorySorosilicate
FormulaCa2Mn2Si4O11(OH)4·2H2O
IMA symbolRz
Strunz classification9.BJ.35
Dana classification57.2.2.1
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/c
Unit cella = 11.95 Å, b = 6.17 Å
c = 9.03 Å, β = 91.37°; Z = 4
Identification
ColorOrange, red-brown
TwinningCommon on {100}
Mohs scale hardness5
StreakApricot
DiaphaneityTranslucent
Optical propertiesBiaxial (-)
Refractive indexnα = 1.663
nβ = 1.715
nγ = 1.734
Birefringenceδ = 0.071
2V angle60°
References

Ruizite is a sorosilicate mineral with formula Ca2Mn2Si4O11(OH)4·2H2O. It was discovered at the Christmas mine in Christmas, Arizona, and described in 1977. The mineral is named for discoverer Joe Ana Ruiz.