Calcium Magnesium Carbonate
CaMg(CO3)2
Chemical name
Calcium Magnesium Carbonate
Mineral name
Dolomite
Chemical formula
CaMg(CO3)2
Crystal system
trigonal
Crystal Class
trigonal-rhombohedral (-3)
Space Group
R-3
Unit cell
a [Å]:4.8012(1)
b [Å]:4.8012(1)
c [Å]:16.002
Molecular weight [g/mol]
184,38
Formula units
Z=3
Frequent crystal surfaces
surfaces often saddle-shaped curved
Twinning
common as simple contact twins
Mohs hardness
3.5 - 4
Density [g/cm3]
2.87
Cleavage
perfect on {10-11}, rhombohedral cleavage
Fracture / Tenacity
conchoidal
Color
white, gray to pink
Streak
white
Transparency
transparent to translucent
Optical character
uniaxial (-)
Refractive Index
nω=1.678-1.681; nε=1.500
Birefringence δ
0.179-0.181
Pleochroism δ
none