Metacinnabar

Formula : HgS

Family: 
Space group: 
Isometric - Hextetrahedral H-M Symbol (4 3m) Space Group: F43m
Dana class: 
2.8.2.3 (2) Sulfides - Including Selenides and Tellurides (2.8) where Am Bn Xp, with (m+n):p=1:1(2.8.2) Sphalerite Group (Isometric: F43m)
High temperature: 
Metacinnabar is stable above about 330C in the pure HgS system.
Geological context: 
Found with cinnabar in mercury deposits formed in near-surface, under low-temperature conditions.

Dernière mise à jour le 25.01.2021

THERMODYNAMICS

Reaction properties

Metacinnabar + 0.375H2O ⇌ 0.5Hg2+2 + 0.75HS- + 0.125S2O3-2

298.15 K, 1 bar log10K: -26.85 ΔH°r:146269 J·mol-1 (Ref.: Internal calculation)
T(°C) 0 25 60 100 150 200 250 300
log10K -29.23 -26.85 -24.20 -21.86 -19.68 -18.08 -16.96 -16.27