Cinnabar(beta)

Formula : HgS

Family: 
Sulfides
Space group: 
Trigonal - Trapezohedral H-M Symbol (3 2) Space Group: P 3121,P 3221
Dana class: 
2.8.14.1 (2)Sulfides - Including Selenides and Tellurides (2.8)where Am Bn Xp, with (m+n):p=1:1 (2.8.14) Dana Group
High temperature: 
At 25C cinnabar is a metastable mineral, a gentle desulphuration can release drops of mercury.
Geological context: 
Low temperature hydrothermal solutions in veins. Oxidized mercury deposits, supergene environment.

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
232.656 -43534 (Ref.: Internal calculation) 46.37 (Ref.: 87pan/mah) Pankratz L. B., 1987, A. D. Mah, and S. W. Watson, Thermodynamic Properties of Sulfides (U. S. Bureau of Mines Bulletin 689, 1987, 427 p).
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.
49.21 11.95 -5.69 (Ref.: 87pan/mah) Pankratz L. B., 1987, A. D. Mah, and S. W. Watson, Thermodynamic Properties of Sulfides (U. S. Bureau of Mines Bulletin 689, 1987, 427 p).
Reaction properties

Cinnabar(beta) + H+ ⇌ HS- + Hg+2

298.15 K, 1 bar log10K: -38.62 ΔH°r: J·mol-1 (Ref.: )
T(°C) 0 25 60 100 150 200 250 300
log10K -41.90 -38.62 -34.92 -31.61 -28.46 -26.11 -24.39 -23.24
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-913.125651 -0.145544 38723.193874 331.549138 -2877942.380493