Mineral - Augelite
Augelite
Chemical Properties
Mineral Class
Phosphates
Toxicity
none
Formula
Al₂[(OH)₃|PO₄]
Unit Cell
a=13.12 b=7.99 c=5.07 β=112° Z=4
Physical Properties
Hardness
4.5 - 5
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {110}, good after { 2 01}, unclear after {001} and { 1 01}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
yellowgreenpinkcolorless
Birefringence
0.014
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
C2/m (12)
Habit
dipyramidal, acicular, prismatic, Rhombohedron, Rhombohedral, tabular
Formation
Through metamorphism of phosphate-containing rocks
In high-temperature, hydrothermal ore deposits
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Augelite
Composition
Elements
Mass
P₂O₅
35.04
SiO₂
49.15
TiO₂
0.89
Al₂O₃
0.31
Fe₂O₃
1.09
MnO
12.85
Sweden (Palache et al. 1952)
Name and first discovery : Named after the ancient Greek word "auge" for "shine," in reference to the striking mother-of-pearl sheen on the cleavage surfaces. First described in 1868.
Chemistry :
Synonyms : Amfihalite, Amphitalite
Varieties :
Abbreviation : Aul
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.