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Mineral speciesFormula
 BunseniteNiO 
Mineralogy
Family: Periclase Group 
Space group: Isometric - Hexoctahedral H-M Symbol (4/m 3 2/m) Space Group: F m3m 
Dana class: 4.2.1.2 (4) Simple Oxides (4.2) with a cation charge of 2+ (A++ O) (4.2.1)Periclase group (Isometric, Fm3m) 
Geological context
High temperature: Bunsenite has probably an hydrothermal origin but a supergene stability cannot be dismissed. 
Geological context: On the one hand given as hydrothermal Ni-U vein and on the other hand as secondary mineral from oxidation zone Ni-U vein. 
Thermodynamics
Individual properties
Molar weight: 74.693 g/mol  ΔGºf-211,138 J/mol ref.  Sº: 37.99 J/mol/K ref. 
  ΔHºf-239,300 J/mol ref.  Cp: 45.01 J/mol/K ref. 
Reaction properties
Chemical reaction:  Bunsenite + 2H+ = Ni+2 + H2O 
log10(Keq) = A + B.T + C.T-1 + D.log10(T) + E.T−2 (with T expressed in Kelvin)
A B C D E
 -3.44589120e+2   -5.40417943e-2   2.34089882e+4   1.23612916e+2   -9.93787187e+5 
Van t'Hoff
@ 25°C, 1 bar: log 10(Keq)12.51
ΔH°r-106,030 J/mol ref.
T (ºC) : 0 25 60 100 150 200 250 300
log 10(Keq):  14.20   12.51   10.55   8.76   6.98   5.54   4.31   3.21 
Maier Kelley
Cp(T) = a + b*10-3T + C*105T-2 (with T expressed in Kelvin)  ref.
a:29.80 J/mol/K 
b:63.73 J/mol/K2 
c:-3.38 J.K/mol 

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