Actinolite

Formula : Ca2(Mg2.25Fe2.5Al0.25)(Si7.75Al0.25)O22(OH)2

Family: 
Amphiboles
Space group: 
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m
High temperature: 
Actinolite stability domain ranges between 400C to 500C, it depends strongly on CO2 fugacity.
Geological context: 
From contact metamorphism of Ca-Mg siliceous sediments; in greenschist facies metamorphics derived from ultramafic or magnesium carbonate rocks.

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
891.615 274.660 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61. -11046383 (Ref.: Internal calculation) -11754650 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61. 601.880 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61. 662.91 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61.
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.
789.11 279.46 -186.24 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61.
Reaction properties

Actinolite + 15H+ + 7H2O ⇌ 0.5Al+3 + 2Ca+2 + 2.5Fe+2

298.15 K, 1 bar log10K: 7.13 ΔH°r:-181662 J·mol-1 (Ref.: 19bla/lac) Blanc, P., Lach, A., Guignot, S., 2019. Mineralogy and suitability of materials for geopolymer production. Brgm, p. 61.
T(°C) 0 25 60 100 150 200 250 300
log10K 9.75 7.13 3.61 0.25 -3.11 -5.92 -8.55 -11.37
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-5095.418243 -0.694950 308253.120077 1813.335082 -18767155.030008