Manganese Carbonate
MnCO3
Chemical name
Manganese Carbonate
Mineral name
Rhodochrosite
Chemical formula
MnCO3
Crystal system
trigonal
Crystal Class
ditrigonal-scalenohedral (-3 2/m)
Space Group
R-3c
Unit cell
a [Å]:4.74
b [Å]:4.74
c [Å]:15.51
Molecular weight [g/mol]
114,95
Formula units
Z=6
Twinning
on {01-12} (contact and lamellar)
Mohs hardness
3.5 - 4.5
Density [g/cm3]
3.3 - 3.6
Cleavage
perfect on {10-11}
Fracture / Tenacity
conchoidal
Color
pink to rose-red, cherry-red, yellow to yellowish gray, brown
Streak
white
Transparency
transparent to translucent
Optical character
uniaxial (-)
Refractive Index
nω=1.814-1.816; nε=1.596
Birefringence δ
0.218
Pleochroism δ
weak