Home > Data consultation > Mineral species
 
Mineral speciesFormula
 CovelliteCuS 
Mineralogy
Space group: Hexagonal - Dihexagonal Dipyramidal HM symbol (6/m 2/m 2/m) Space Group: P 63/mmc 
Dana class: 2.8.12.1II- 2 Sulfide Minerals ; 2.8 Sulfides - Including Selenides and Tellurides where Am Bn Xp, with (m+n):p=1:1 ; 2.8.12 
Geological context
Geological context: Most commonly of secondary origin in the zone of oxidation in sulfide copper deposits. Rarely of primary hydrothermal origin. Widespread in most copper deposits; common an iridescent tarnish on other sulfides. 
Thermodynamics
Individual properties
Molar weight: 95.612 g/mol  ΔGºf-52,694 J/mol ref.  Sº: 66.53 J/mol/K ref. 
  ΔHºf-52,300 J/mol ref.  Cp: 47.64 J/mol/K ref. 
Reaction properties
Chemical reaction:  Covellite + 0.375H2O = Cu+ + 0.75HS- + 0.125S2O3-2 
log10(Keq) = A + B.T + C.T-1 + D.log10(T) + E.T−2 (with T expressed in Kelvin)
A B C D E
 -7.53646430e+2   -1.20496280e-1   3.41072020e+4   2.74700316e+2   -2.51417311e+6 
Van t'Hoff
@ 25°C, 1 bar: log 10(Keq)-23.73
ΔH°r-767,051 J/mol ref.
T (ºC) : 0 25 60 100 150 200 250 300
log 10(Keq):  -26.11   -23.73   -21.09   -18.76   -16.57   -14.98   -13.85   -13.16 
Maier Kelley
Cp(T) = a + b*10-3T + C*105T-2 (with T expressed in Kelvin)  ref.
a:44.35 J/mol/K 
b:11.05 J/mol/K2 
c:0.00 J.K/mol 

Home | Legal information | Private area | Contact us | RSS 2.0 BRGM − 3, avenue Claude Guillemin − 45060 Orléans Cedex 2