Rodalquilarite

Rodalquilarite
Rodalquilarite crystals from a cavity in alunite
General
CategoryTellurite mineral
FormulaH3Fe3+2(Te4+O3)4Cl
IMA symbolRaq
Strunz classification4.JL.05
Crystal systemTriclinic
Crystal classPinacoidal (1)
(same H-M symbol)
Space groupP1
Unit cella = 8.95 Å, b = 5.09 Å
c = 6.63 Å; α = 103.17°
β = 107.08°, γ = 77.87°; Z = 1
Identification
ColorEmerald- to grass-green
Crystal habitCrusts of stout crystals
CleavageOne good cleavage plane
TenacityVery brittle
Mohs scale hardness2 - 3
LusterGreasy
StreakGreenish yellow
DiaphaneitySemitransparent
Specific gravity4.97 - 5.15
Optical propertiesBiaxial (-)
Refractive indexnα = 2.100 nγ = 2.200
Birefringenceδ = 0.100
2V angle38°
References

Rodalquilarite is a rare iron tellurite chloride mineral with formula H3Fe3+2(Te4+O3)4Cl or Fe2(TeO2OH)3(TeO3)Cl. Rodalquilarite crystallizes in the triclinic system and typically occurs as stout green prisms and encrustations.