Constituent
Name
Mg-Siderite
IMA name
Magnesite-Siderite series
Class
non-silicate mineral
Compound type
carbonate
Comments
full miscibility of the solid solution
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Formula
Fe2+0.66Mg2+0.305Mn2+0.025CO3
Chemical formula
(Fe0.66,Mg0.305,Mn0.025)CO3
Elemental formula
(Mg2+)0.306 (Fe2+)0.662 (Mn2+)0.024 (Ca2+)0.008 C O (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Mg2+ Magnesium(II) cation element 0.306 1.0 constituent cation main
Fe2+ Iron(II) cation element 0.662 1.0 constituent cation main
Mn2+ Manganese(II) cation element 0.024 1.0 constituent cation main
Ca2+ Calcium cation element 0.008 1.0 constituent cation main
(CO3)2 Carbonate anion chemical function 1 1.0 anionic radical main
Composition comments
Mg+Fe=1
Chemical functions
  Function Number
(CO3)2 1
Chemical bonds
  Bond Number
Mg2+O n
Fe2+O n
CO2/3 3
Oxides
Formula MgO FeO CO2
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
105.2 g/mol
Density
3.635 g/cm3
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.225
Refraction index nα
1.815
Refraction index nβ
1.59
Dispersion V
very strong to strong
Color
yellow-green
Diaphaneity
transparent to subtranslucent
Luster
vitreous