Arcanite

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Arcanite
Arcanite.jpg
Arcanite
General
Category Sulfate mineral
Formula
(repeating unit)
K2SO4
Strunz classification 7.AD.05
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Pmcn
Unit cell a = 5.77, b = 10.07
c = 7.48 [Å]; Z = 4
Identification
Color White to colorless, yellow
Crystal habit Tabular crystals, typically in crusts and coatings
Twinning Cyclic on {110}
Cleavage Good on {010} and {001}
Mohs scale hardness 2
Luster Vitreous
Streak White
Diaphaneity Transparent to translucent
Specific gravity 2.66
Optical properties Biaxial (+)
Refractive index nα = 1.494 nβ = 1.495 nγ = 1.497
Birefringence δ = 0.004
2V angle Measured: 67°
References [1][2][3]

Arcanite is a potassium sulfate mineral with formula: K2SO4.

Arcanite was first described in 1845 for an occurrence in old pine railroad ties in the Santa Ana tin mine, Trabuco Canyon, Santa Ana Mountains, Orange County, California, US.[1][3] It has also been reported from hydrothermal deposits in the Cesano geothermal field, Latium, Italy; in bat guano on the Chincha Islands of Peru; and in caves in Western Australia, South Africa and Namibia.[3]

References[edit]