Calcite

Formula : CaCO3

Family: 
Carbonates
Space group: 
Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: R 3c
Dana class: 
14.1.1.1 (14) Anhydrous Carbonates (14.1) with Simple Formula A+ CO3 (14.1.1) Calcite Group (Trigonal: R3c)
High temperature: 
Very low temperature mineral, subsurface conditions, hydrothermal systems
Geological context: 
Widespread mineral in hydrothermal systems and also as a biological secretion.

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
 V°
cm3·mol-1
 ΔGºf
J·mol-1
 ΔHºf
J·mol-1
 Sº
J·mol-1·k-1
 CP
J·mol-1·K-1
100.087 36.934 (Ref.: 78hel/del,82plu/bus) -1129109 (Ref.: 06bla/pia) Blanc P., Piantone P., Lassin A. et Burnol A., 2006. Thermochimie : Selection de constantes thermodynamiques pour les elements majeurs, le plomb et le cadmium. Rapport final. Rapport BRGM 54902-FR -1207605 (Ref.: Internal calculation) 91.780 (Ref.: 82plu/bus) Plummer, L.N. and Busenberg, E., 1982. The Solubilities of Calcite, Aragonite, and Vaterite in CO2-H2O Solutions Between 0 and 90 C and an Evaluation of the Aqueous Model of the System CaCO3-CO2-H2O. Geochimica et Cosmochimica Acta, Vol. 46, p. 1011-1040. 83.47 (Ref.: 95rob/hem) Robie R.A., and Hemingway B.S., 1995. Thermodynamic properties of minerals and related substances at 298.15 K and 1 Bar (105 Pascals) pressure and at higher temperatures. U.S. Geol. Survey Bull., 2131, 461 pp.
CP(T) = a + b·T + ·c·T-2 (T in Kelvin)
a
J·mol-1·K-1
 b * 103
J·mol-1·K-2
 c * 10-5
J·K·mol-1
 Maier Kelley Ref.
99.72 26.92 -21.58 (Ref.: 95rob/hem) Robie R.A., and Hemingway B.S., 1995. Thermodynamic properties of minerals and related substances at 298.15 K and 1 Bar (105 Pascals) pressure and at higher temperatures. U.S. Geol. Survey Bull., 2131, 461 pp.
Reaction properties

Calcite + H+ ⇌ HCO3- + Ca+2

298.15 K, 1 bar log10K: 1.85 ΔH°r:-25325 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K 2.22 1.85 1.34 0.79 0.11 -0.58 -1.33 -2.24
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-850.097688 -0.139471 46880.815547 309.647554 -2659139.927884