Rodalquilarite

Rodalquilarite

Rodalquilarite crystals from a cavity in alunite
General
Category Tellurite mineral
Formula
(repeating unit)
H3Fe3+2(Te4+O3)4Cl
Strunz classification 4.JL.05
Crystal symmetry Triclinic pinacoidal
Space group: P1 or P1
Unit cell a = 8.95 Å, b = 5.09 Å, c = 6.63 Å; α = 103.17°, β = 107.08°, γ = 77.87°; Z=1
Identification
Color Emerald- to grass-green
Crystal habit Crusts of stout crystals
Crystal system Triclinic
Cleavage One good cleavage plane
Tenacity Very brittle
Mohs scale hardness 2 - 3
Luster Greasy
Streak Greenish yellow
Diaphaneity Semitransparent
Specific gravity 4.97 - 5.15
Optical properties Biaxial (-)
Refractive index nα = 2.100 nγ = 2.200
Birefringence δ = 0.100
2V angle 38°
References [1][2][3]

Rodalquilarite is a rare iron tellurite chloride mineral with formula H3Fe3+2(Te4+O3)4Cl[1] or Fe2(TeO2OH)3(TeO3)Cl.[2] Rodalquilarite crystallizes in the triclinic system and typically occurs as stout green prisms and encrustations.

Discovery and occurrence

Green rodalquilarite crystals in a vug in pink alunite from Chile

Rodalquilarite was first described in 1968 for an occurrence in the Rodalquilar gold deposit of Almeria, Spain and was named for the discovery locality. It has also been reported from the Wendy open pit mine, El Indio-Tambo district, Coquimbo Region of Chile and the mines of Tombstone, Arizona.[1] It is found in the oxidized zone of tellurium-bearing gold deposits. It occurs associated with emmonsite, native gold, alunite, jarosite, quartz, native tellurium, mackayite and sonoraite.[1]

References