Constituent
Name
Siderite
IMA name
Siderite
Class
non-silicate mineral
Compound type
carbonate
Constituent abundance in material
Relevance
main - minor
Arrangement
heterogeneous in multi-phases
Chemical composition
Formula
$Fe^{2+}CO_3$
Chemical formula
FeCO3
Elemental formula
(Fe2+) C O (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Fe^{2+}$ Iron(II) cation element 1 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 1 anionic radical main
Chemical functions
  Function Number
$(CO_3)^{2-}$ 1
Chemical bonds
  Bond Number
$\cdot Fe^{2+} \cdot O^{-}-$ 2
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $FeO$ $CO_{2}$
Mass fraction (%) 62.01 37.99

Strunz

Class
carbonates - nitrates (05)
Division
carbonates without additional anions, without H2O (05.A)
Family
Alkali-earth (and other M2+) carbonates (05.AB)
Code
05.AB.05

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with simple formula A+CO3 (14.01)
Group
Calcite group (Trigonal: R-3c) (14.01.01)
Code
14.01.01.03
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Molar mass
115.86 $g/mol$
Density
3.96 $g/cm^3$
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.215 - 0.242
Refraction index $n_{\alpha}$
1.785 - 1.875
Refraction index $n_{\beta}$
1.57 - 1.633
Color
Yellowish brown, Brown, Gray, Yellowish gray, Greenish gray
Diaphaneity
translucent to subtranslucent
Luster
vitreous