Constituent
Name
Alstonite
IMA name
Alstonite
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
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
……C…O-2/3 3
Oxides
Formula BaO CaO CO2
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/cm3
Refringence type
biaxial
Refringence sign
negative
Birefringence
0.1460
Refraction index nα
1.526
Refraction index nβ
1.671
Refraction index nγ
1.672
Dispersion V
r > v weak
Color
colorless, gray, white, pink
Diaphaneity
transparent to translucent
Luster
vitreous