Brucite

Formula : Mg(OH)2

Family: 
Hydroxides
Space group: 
Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: P 3m1
Dana class: 
6.2.1.1 (6) Hydroxides and Oxides Containing Hydroxyl (6.2) where X++ (OH)2 (6.2.1)Brucite group (Rhombohedral: P3m1)
High temperature: 
Occurs in metamorphic environment: low to high temperature.
Geological context: 
It occurs in serpentine, in chlorite or dolomitic schists, or in crystalline limestones as an alteration product of periclase.

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
58.320 24.630 (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. -831991 (Ref.: 08bla) Blanc P. (2008) : Thermoddem - Selection de proprietes thermodynamiques pour les principales especes aqueuses et minerales porteuses de fer. Rapport final. Rapport BRGM/RP-56587-FR, 70p. -924142 (Ref.: 08bla) Blanc P. (2008) : Thermoddem - Selection de proprietes thermodynamiques pour les principales especes aqueuses et minerales porteuses de fer. Rapport final. Rapport BRGM/RP-56587-FR, 70p. 59.427 (Ref.: Internal calculation) 77.27 (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.
102.20 15.11 -26.17 (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

Brucite + 2H+ ⇌ Mg+2 + 2H2O

298.15 K, 1 bar log10K: 17.11 ΔH°r:-114518 J·mol-1 (Ref.: 08bla) Blanc P. (2008) : Thermoddem - Selection de proprietes thermodynamiques pour les principales especes aqueuses et minerales porteuses de fer. Rapport final. Rapport BRGM/RP-56587-FR, 70p.
T(°C) 0 25 60 100 150 200 250 300
log10K 18.96 17.11 15.02 13.15 11.34 9.92 8.75 7.71
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-356.416352 -0.053167 24317.829325 128.731219 -952868.816597