Mineral - Arcanite
Arcanite
Chemical Properties
Mineral Class
Sulphates
Toxicity
none
Formula
K₂SO₄
Unit Cell
a=7.75 b=10.10 c=5.76 Z=4
Physical Properties
Hardness
2
Streak
white
Density
Normal (2-3,5)
Cleavage
Good after {010} and {001}
Fracture
nd
Tenacity
Brittle
Optical Properties
Color
whitecolorless
Birefringence
0.004
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnma (62)
Habit
granular, massive, tabular
Formation
Secondary, in caves and mines by bat guano
Secondary, through hydrothermal alteration
In and around volcanic fumaroles
Paragenesis
Twinning
Rotationszwillinge nach (110)
Rarity
Rarely
Synonyms
Arcanite
Composition
Elements
Mass
SO₃
45.37
Na₂O
0.01
K₂O
47.50
(NH₄)₂O
5.14
Peru (Palache et al. 1952)
Name and first discovery : Named in 1845 by Wilhelm Carl von Haidinger after the Latin word "arcanum duplicatum" for "double secret", a medieval alchemical term. The original material was a precipitation product on the surface of discarded railway ties that had been used in the Santa Ana tin mine in California, USA.
Synonyms : Arcanite
Varieties : Taylorite
Abbreviation : Acn
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.