Mineral phase
IMA name
Rhodochrosite
Secondary names
Manganese carbonate; Mn carbonate
IMA Code
Rds
Type
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
$Mn^{2+}CO_3$
Chemical formula
MnCO3
Elemental formula
(Mn2+) C O (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mn^{2+}$ Manganese(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
$\cdot Mn^{2+} \cdot O^{-}-$ 2
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $MnO$ $CO_{2}$
Mass fraction (%) 61.71 38.29

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
14.01.01.04
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Molar mass
114.95 $g/mol$
Density
3.69 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.218
Refraction index $n_o$ (w)
1.814 - 1.816
Refraction index $n_e$ (e)
1.596 - 1.598
Pure color
red
Color
Pinkish red, Red, Rose red, Yellowish gray, Brown
Diaphaneity
translucent to subtranslucent
Luster
vitreous
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