Zinc Aluminate Spinell
ZnAl2O4
|
Chemical name
Zinc Aluminate Spinell |
|
Mineral name
Gahnite |
|
Chemical formula
ZnAl2O4 |
|
Melting point [°C]
N/A |
|
Crystal system
cubic |
|
Crystal Class
cubic-hexoctahedral (4/m -3 2/m) |
|
Space Group
Fd-3m |
|
Unit cell
a [Å]:8.09 b [Å]:8.09 c [Å]:8.09 |
|
Molecular weight [g/mol]
183.34 |
|
Formula units
Z=8 |
|
Frequent crystal surfaces
{111}, {110}, {211}, occasionally {100} |
|
Twinning
on (111) |
|
Mohs hardness
7.5 - 8 |
|
Density [g/cm3]
4.6 |
|
Cleavage
indistinct |
|
Fracture / Tenacity
brittle, uneven to conchoidal |
|
Color
blue, green, yellowish brown, greenish black |
|
Streak
gray to white |
|
Transparency
translucent to opaque |
|
Luster
resinous to vitreous |
|
Optical character
isotropic |
|
Refractive Index
n=1.79-1.80 |
|
Pleochroism δ
none |
