Mineral phase
IMA name
Coalingite
IMA Code
Clg
Type
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
$Mg_{10}Fe^{3+}_2(CO_3)(OH)_{24} \bullet 2(H_2O)$
Chemical formula
Mg10Fe3+2(CO3)(OH)24•2(H2O)
Elemental formula
(Mg2+)10 (Fe3+)2 C O3 (O-)26 H28
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Mg^{2+}$ Magnesium(II) cation element 10 constituent cation main
$Fe^{3+}$ Iron(III) cation element 2 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 1 anionic radical main
$(OH)^-$ Hydroxide anion chemical function 24 anionic radical main
$H_2O$ Water molecule 2 hydration main
Chemical functions
  Function Number
$(CO_3)^{2-}$ 1
$(OH)^-$ 24
$R-OH$ 2
Chemical bonds
  Bond Number
$\cdot Mg^{2+} \cdot O^{-}-$ 20
$\cdot (\cdot) Fe^{3+} \cdot O^{-}-$ 6
$-O-H$ 2
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
$O^--H$ 1
Oxides
Formula $MgO$ $Fe_{2}O_{3}$ $H_{2}O$ $CO_{2}$
Mass fraction (%) 46.92 18.59 29.36 5.12

Strunz

Class
carbonates - nitrates (05)
Division
carbonates with additional anions, with H2O (05.D)
Family
with medium-sized cations (05.DA)
Code
05.DA.55

Dana

Major class
carbonates, nitrates, borates (V)
Class
carbonates - hydroxyl or halogen (16b)
Type
-unclassified- (16b.07)
Group
-Coalingite- group (16b.07.06)
Code
16b.07.06.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
dihexagonal-dipyramidal
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Molar mass
858.96 $g/mol$
Density
2.33 - 2.42 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.0280 - 0.0450
Refraction index $n_o$ (w)
1.588 - 1.635
Refraction index $n_e$ (e)
1.56 - 1.59
Pure color
brown
Color
bronze brown, light brown, reddish brown
Luster
resinous
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