Silicon Dioxide Iron Chromium doped
SiO2:FeCr
Chemical name
Silicon Dioxide Iron Chromium doped
Mineral name
Quarz
Chemical formula
SiO2:FeCr
Melting point [°C]
1700
Crystal system
trigonal
Crystal Class
trigonal-trapezohedral (32)
Space Group
P3_1 21, P3_2 21
Unit cell
a [Å]:4.91
b [Å]:4.91
c [Å]:5.40
Molecular weight [g/mol]
60.08
Formula units
Z=3
Frequent crystal surfaces
{10-11}, {01-11}, {10-10}
Twinning
dauphine law, brazil law, japan law
Mohs hardness
7
Density [g/cm3]
2.65
Cleavage
none
Fracture / Tenacity
brittle, conchoidal
Color
dark brown
Streak
white
Transparency
transparent to opaque
Optical character
uniaxial (+)
Refractive Index
nω=1.543; nε=1.552
Birefringence δ
0.009
Pleochroism δ
none