Mineral phase
IMA name
Eitelite
Secondary names
Natrium magnesium carbonate; Na-Mg carbonate
IMA Code
Eit
Type
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
$Na_2Mg(CO_3)_2$
Chemical formula
Na2Mg(CO3)2
Elemental formula
(Na+)2 (Mg2+) C2 O2 (O-)4
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Na^+$ Sodium cation element 2 constituent cation main
$Mg^{2+}$ Magnesium(II) cation element 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
$Na^+ \cdot O^{-}-$ 2
$\cdot Mg^{2+} \cdot O^{-}-$ 2
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $Na_{2}O$ $MgO$ $CO_{2}$
Mass fraction (%) 32.57 21.18 46.25

Strunz

Class
carbonates - nitrates (05)
Division
carbonates without additional anions, without H2O (05.A)
Family
Alkali and alkali-earth carbonates (05.AC)
Code
05.AC.05

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with Compound Formula A+2B++(CO3)2 (14.03)
Group
-Eitelite- group (14.03.02)
Code
14.03.02.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
rhombohedral
Crystal class symbol
-3 (S6)
Crystal spacegroup
R-3
Molar mass
190.30 $g/mol$
Density
2.737 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.1550
Refraction index $n_o$ (w)
1.6052
Refraction index $n_e$ (e)
1.4502
Pure color
colorless
Color
colorless, white
Diaphaneity
transparent
Luster
vitreous
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