Wollastonite

Formula : CaSiO3

Space group: 
Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1
Dana class: 
65.2.1.1a (65) Inosilicate Single-Width Unbranched Chains, W=1 (65.2) with chains P=3 (65.2.1) Wollastonite group
High temperature: 
It is a high temperature mineral ranguing between around 400C to up to 1000C, its stability is strongly dependent on the CO2 fugacity.
Geological context: 
Common in thermally metamorphosed siliceous carbonates, the intruding igneous rock, and skarn deposits along their contact; also in some alkalic igneous rocks and carbonatites. This mineral occurs also in slags from smelters and MSWI bottom ash.

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
116.162 39.930 -1544837 -1630145 82.006 85.26
Reaction properties

Wollastonite + 2H+ + H2O ⇌ Ca+2 + H4SiO4

298.15 K, 1 bar log10K: 14.02 ΔH°r: -88220 J·mol-1
T(°C) 0 25 60 100 150 200 250 300
log10K 15.44 14.02 12.41 10.94 9.48 8.30 7.30 6.39