Tremolite

Formula : (Ca2Mg5)Si8O22(OH)2

Space group: 
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Dana class: 
66.1.3a.1 (66) Inosilicate Double-Width Unbranched Chains, W=2(66.1) Dana Type (66.1.3a) Group 2, the calcic amphiboles
High temperature: 
Tremolite 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 11.06.2018

THERMODYNAMICS

Individual properties (298.15 K)
M
g·mol-1
cm3·mol-1
ΔGºf
J·mol-1
ΔHºf
J·mol-1
J·mol-1·k-1
CP
J·mol-1·K-1
812.366 272.920 -11575331 -12303000 548.900 650.21
Reaction properties

Tremolite + 14H+ + 8H2O ⇌ 2Ca+2 + 5Mg+2 + 8H4SiO4

298.15 K, 1 bar log10K: 67.24 ΔH°r: -520914 J·mol-1
T(°C) 0 25 60 100 150 200 250 300
log10K 75.63 67.24 57.74 49.23 40.93 34.28 28.60 23.35