Brookite
TiO2
Crystal symmetry |
Orthorhombic 2/m 2/m 2/m dipyramidal |
Unit cell |
Z = 8 |
Formula mass |
79.88 g[1] |
Color |
Brown, yellowish brown, or black |
Cristal habit |
Tabular and striated, pyramidal or pseudohexagonal |
Crystal system |
Orthorhombic |
Twinning |
On {120}, uncertain |
Cleavage |
Poor on {120}, in traces on {001} |
Mohs Scale hardness |
5 1/2 to 6 |
Specific gravity |
4.08 to 4.18 |
Optical properties |
Biaxial (+) |
Refractive index |
nα = 2.583 |
Birefringence |
∂ = 0.117 |
2V angle |
Calculated: 12° to 2° |