Lizardite

Formula : Mg3Si2O5(OH)4

Space group: 
Triclinic Pedial or Pinacoidal HM symbol (1 or -1) Space Group: P1
Dana class: 
71.1.2b.2VIII- 71 Phyllosilicate Minerals ; 71.1 Phyllosilicates Phyllosilicate Sheets of Six-Membered Rings with 1:1 layers ; 71.1.2b Serpentine group (Lizardite subgroup)
High temperature: 
stable below 75 C
Geological context: 
Serpentinization alteration of Mg silicates below 75 deg. C.

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
277.112 107.500 (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. -4032889 (Ref.: Internal calculation) -4362000 (Ref.: 04eva) Evans B. (2004) The serpentine multisystem revisited: Chrysotile is metastable, International Geology Review, 46, 479-506 216.330 (Ref.: 04eva) Evans B. (2004) The serpentine multisystem revisited: Chrysotile is metastable, International Geology Review, 46, 479-506 274.14 (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.
296.63 167.14 -64.29 (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

Lizardite + 6H+ ⇌ 3Mg+2 + 2H4SiO4 + H2O

298.15 K, 1 bar log10K: 33.09 ΔH°r:-242552 J·mol-1 (Ref.: 04eva) Evans B. (2004) The serpentine multisystem revisited: Chrysotile is metastable, International Geology Review, 46, 479-506
T(°C) 0 25 60 100 150 200 250 300
log10K 36.93 33.09 28.62 24.58 20.68 17.60 15.03 12.70
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1804.533847 -0.247561 115467.244341 644.051927 -6178644.206788