Iron Carbonate
FeCO3
Chemical name
Iron Carbonate
Mineral name
Siderite
Chemical formula
FeCO3
Crystal system
trigonal
Crystal Class
ditrigonal-scalenohedral (-3 2/m)
Space Group
R-3c
Unit cell
a [Å]:4.69
b [Å]:4.69
c [Å]:15.38
Formula units
Z=6
Twinning
uncommon lamellar on {01-12}
Mohs hardness
4 - 4.5
Density [g/cm3]
3.7 - 3.9
Cleavage
perfect on {10-11}
Fracture / Tenacity
uneven to conchoidal
Color
yellow, brown, black
Streak
white to bright yellowish
Transparency
transparent to translucent
Optical character
uniaxial (-)
Refractive Index
nω=1.875; nε=1.633
Birefringence δ
0.242