Constituent
Name
Huntite
IMA name
Huntite
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
CaMg3(CO3)4
Chemical formula
CaMg3(CO3)4
Elemental formula
(Ca2+) (Mg2+)3 C4 O4 (O-)8
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Ca2+ Calcium cation element 1 constituent cation main
Mg2+ Magnesium(II) cation element 3 constituent cation main
(CO3)2- Carbonate anion chemical function 4 anionic radical main
Chemical functions
  Function Number
(CO3)2- 4
Chemical bonds
  Bond Number
· Ca2+ · O-- 2
· Mg2+ · O-- 6
……C…O-2/3 3
Oxides
Formula CaO MgO CO2
Mass fraction (%) 15.88 34.25 49.87

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.25

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with Compound Formula A+2B++2(CO3)4 (14.04)
Group
-Huntite- group (14.04.03)
Code
14.04.03.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
trapezohedral
Crystal class symbol
32 (D3)
Crystal spacegroup
R32
Molar mass
353.03 g/mol
Density
2.696 g/cm3
Refringence type
uniaxial
Refringence sign
negative
Refraction index nα
1.622
Refraction index nβ
1.615
Color
white, lemon white
Luster
earthy