Mineral phase
IMA name
Alstonite
Secondary names
Barium calcium carbonate; Ba-Ca carbonate
IMA Code
Asn
Class
non-silicate mineral
Compound type
carbonate
Formula
BaCa(CO3)2
Chemical formula
BaCa(CO3)2
Elemental formula
(Ba2+) (Ca2+) C2 O2 (O-)4
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
Ba2+ Barium cation element 1 constituent cation main
Ca2+ Calcium cation element 1 constituent cation main
(CO3)2 Carbonate anion chemical function 2 anionic radical main
Chemical functions
  Function Number
(CO3)2 2
Chemical bonds
  Bond Number
Ba2+O 2
Ca2+O 2
3
Oxides
Formula BaO CaO CO_{2}
Mass fraction (%) 51.55 18.85 29.59

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.35

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with compound formula A+B++(CO3)2 (14.02)
Group
-Alstonite- group (14.02.05)
Code
14.02.05.01
Phase type
crystalline
Crystal system
triclinic
Crystal class
pedial
Crystal class symbol
1 (C1)
Crystal spacegroup
P1
Comments
P1 (pedial, 1 (C1)) or P-1 (pinacoidal, -1 (Ci)) group
Molar mass
297.42 g/mol
Density
3.69 - 3.71 g/cm^3
State NTP
solid
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.1460
Refraction index n_{\alpha}
1.526
Refraction index n_{\beta}
1.671
Refraction index n_{\gamma}
1.672
Dispersion V
r > v weak
Pure color
colorless
Color
colorless, gray, white, pink
Diaphaneity
transparent to translucent
Luster
vitreous