Mineral - Brazilianite
Brazilianite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
NaAl₃[(OH)₂|PO₄]₂
Unit Cell
a=11.23 b=10.14 c=7.10 β=97° Z=4
Physical Properties
Hardness
5.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Distinct after {010}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
greencolorless
Birefringence
0.020
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
prismatic, radial
Formation
Magmatic, in Pegmatites
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Brazilianite
Composition
Elements
Mass
P₂O₅
37.97
Al₂O₃
43.82
Na₂O
8.42
K₂O
0.37
H₂O
9.65
Brazil (Palache et al. 1952)