Mineral phase
IMA name
Dolomite group
Type
Class
non-silicate mineral
Compound type
carbonate
Comments
Other endmembers are: Kutnohorite and Minrecordite
Chemical composition
Formula
$Ca(A)(CO_3)_2 \ \ \ \ \ $ where $A = Mg,Fe^{2+},Mn$ and/or $Zn$
Chemical formula
Ca(Mg,Fe,Mn,Zn)(CO3)2
Elemental formula
(Ca2+) (Mg2+)0-1 (Zn2+)0-1 (Mn2+)0-1 (Fe2+)0-1 C2 O2 (O-)4
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Ca^{2+}$ Calcium cation element 1 constituent cation main
$Mg^{2+}$ Magnesium(II) cation element 0 - 1 constituent cation main
$Zn^{2+}$ Zinc(II) cation element 0 - 1 constituent cation main
$Mn^{2+}$ Manganese(II) cation element 0 - 1 constituent cation main
$Fe^{2+}$ Iron(II) cation element 0 - 1 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 2 anionic radical main
Chemical functions
  Function Number
$(CO_3)^{2-}$ 2
Chemical bonds
  Bond Number
$\cdot Ca^{2+} \cdot O^{-}-$ 2
$\cdot Mg^{2+} \cdot O^{-}-$
$\cdot Fe^{2+} \cdot O^{-}-$
$\cdot Mn^{2+} \cdot O^{-}-$
$\cdot Zn^{2+} \cdot O^{-}-$
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $CaO$ $CO_{2}$ $MgO$ $MnO$ $FeO$ $ZnO$
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.10

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with compound formula A+B++(CO3)2 (14.02)
Group
Dolomite group (Trigonal: R-3) (14.02.01)
End-members
Phase type
crystalline
Crystal system
trigonal
Crystal class
rhombohedral
Crystal class symbol
-3 (S6)
Crystal spacegroup
R-3
Molar mass
184.4-225.49 $g/mol$
Density
2.8 - 3.45 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
negative
Diaphaneity
transparent to subtranslucent
Luster
various
Links