Mineral - Alacránite
Alacránite
Chemical Properties
Mineral Class
Sulfides and sulfosalts
Toxicity
Formula
As₈S₉
Unit Cell
a=9.94 b=9.37 c=8.91 β=102° Z=2
Physical Properties
Hardness
1.5
Streak
orangeyellowyellow orange
Density
Normal (2-3,5)
Cleavage
Imperfect on {100}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
redorangeyelloworange red
Birefringence
0.130
Luster
Vitreous,
Greasy,
Resinous
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2/c (13)
Habit
crusty, massive, acicular, prismatic, prismatic, tabular
Formation
Hydrothermal overprinting of polymetallic deposits; in fumaroles from a burning coal mine
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Alacránite
Composition
Elements
Mass
As
67.80
S
32.20
Czech Republic (Popova et al. 1986)
Name and first find : Named after the Chilean type locality "Alacrán Mine" where the mine was discovered in 1985.
Chemistry :
Synonyms :
Varieties :
Abbreviation : Acr
literature
Popova, VI, Popov, VA, Clark, A., Polyakov, VO, & Borisovski, SE (1986). Alacranite As8S9; a new mineral. Proceedings of the Russian mineralogical society (ZVMO) , 115 , 360-368.