Mineral phase
IMA name
Calcite
Secondary names
Calcium carbonate; Ca carbonate
IMA Code
Cal
CAS number
471-34-1
Type
Class
non-silicate mineral
Compound type
carbonate
Chemical composition
Formula
$CaCO_3$
Chemical formula
CaCO3
Elemental formula
(Ca2+) C O (O-)2
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Ca^{2+}$ Calcium cation element 1 constituent cation main
$(CO_3)^{2-}$ Carbonate anion chemical function 1 anionic radical main
Chemical functions
  Function Number
$(CO_3)^{2-}$ 1
Chemical bonds
  Bond Number
$\cdot Ca^{2+} \cdot O^{-}-$ 2
$\dddot - \dddot - C \dddot - O^{-2/3}$ 3
Oxides
Formula $CaO$ $CO_{2}$
Mass fraction (%) 56.03 43.97

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.05

Dana

Major class
carbonates, nitrates, borates (V)
Class
anhydrous carbonates (14)
Type
with simple formula A+CO3 (14.01)
Group
Calcite group (Trigonal: R-3c) (14.01.01)
Code
14.01.01.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Molar mass
100.09 $g/mol$
Density
2.71 $g/cm^3$
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-solid from Aragonite > 300 °C
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.172
Refraction index $n_o$ (w)
1.658
Refraction index $n_e$ (e)
1.486
Pure color
colorless
Color
colorless, white, pink, yellow, brown
Diaphaneity
transparent to translucent
Luster
vitreous
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