Aluminium Hydroxide
Al(OH)3
|
Chemical name
Aluminium Hydroxide |
|
Mineral name
Gibbsite |
|
Chemical formula
Al(OH)3 |
|
Melting point [°C]
300 |
|
Crystal system
monoclinic |
|
Crystal Class
monoclinic-prismatic (2/m) |
|
Space Group
P2_1/m |
|
Unit cell
a [Å]:8.64 b [Å]:5.07 c [Å]:9.72 |
|
Molecular weight [g/mol]
78 |
|
Formula units
Z=8 |
|
Frequent crystal surfaces
{001}, {101}, {110} |
|
Twinning
on {001}, rare on {100}, {110} |
|
Mohs hardness
2.5 - 3.5 |
|
Density [g/cm3]
2.3 - 2.4 |
|
Cleavage
perfect on (001) |
|
Fracture / Tenacity
uneven |
|
Color
colorless, white, gray, green, blue |
|
Streak
white |
|
Transparency
transparent to translucent |
|
Luster
vitreous, pearly, dull |
|
Optical character
biaxial (+) |
|
Refractive Index
nα=1.568-1.570; nβ=1.568-1.570; nΥ=1.586-1.587 |
|
Birefringence δ
0.018 |
