Constituent
Name
Fe-Magnesite
IMA name
Magnesite-Siderite series
Class
non-silicate mineral
Compound type
carbonate
Comments
full miscibility of the solid solution
Constituent abundance in material
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Chemical composition
Formula
$Mg^{2+}_{0.67}Fe^{2+}_{0.325}CO_3$
Chemical formula
(Mg0.67,Fe0.325)CO3
Elemental formula
(Mg2+)0.669 (Fe2+)0.326 (Mn2+)0.004 (Ca2+)0.001 C O (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg^{2+}$ Magnesium(II) cation element 0.669 1.0 constituent cation main
$Fe^{2+}$ Iron(II) cation element 0.326 1.0 constituent cation main
$Mn^{2+}$ Manganese(II) cation element 0.004 1.0 constituent cation main
$Ca^{2+}$ Calcium cation element 0.001 1.0 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 1 1.0 anionic radical main
Composition comments
Mg+Fe=1
Chemical functions
  Function Number
$(CO_3)^{2-}$ 1
Chemical bonds
  Bond Number
$\cdot Mg^{2+} \cdot O^{-}-$ n
$\cdot Fe^{2+} \cdot O^{-}-$ n
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $MgO$ $FeO$ $CO_{2}$
Mass fraction (%)

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)
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Molar mass
94.55 $g/mol$
Density
3.31 $g/cm^3$
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.205
Refraction index $n_{\alpha}$
1.755
Refraction index $n_{\beta}$
1.55
Dispersion V
very strong to strong
Color
yellow-green
Diaphaneity
transparent to subtranslucent
Luster
vitreous