Mineral - Wavellite
Wavellite
Chemical Properties
Mineral Class
Phosphates
Toxicity
none
Formula
Al₃(PO₄)₂(OH)₃ · 5H₂O
Unit Cell
a=9.62 b=17.36 c=6.99 Z=4
Physical Properties
Hardness
3.5 - 4
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {110}, distinct after {101} and {010}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
whiteyellowgreen
Birefringence
0.026
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnma (62)
Habit
spherical, radial, grape-shaped
Formation
Secondary, resulting from hydrothermal alteration or supergene weathering of aluminum-bearing minerals/rocks under the influence of phosphoric acid solutions, often in fractures of siliceous shales
Paragenesis
Twinning
Rarity
Common
Synonyms
Wavellite
Composition
Elements
Mass
P₂O₅
33.40
Al₂O₃
37.44
Fe₂O₃
0.64
F
2.79
H₂O
26.45
O=F₂
1.17
Ireland (Palache et al. 1952)
Groups and Members
Wavellite-Group