Bunsenite

Formula : NiO

Family: 
Oxides
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)
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.

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
74.693 10.970 (Ref.: 78hel/del) Helgeson, H.C., Delany, J.M, Nesbitt, H.W., and Bird, D.K., 1978. Summary and Critique of the Thermodynamic Properties of Rock Forming Minerals: Amer. J. Sci., 278A, 229 pp. -211138 (Ref.: Internal calculation) -239300 (Ref.: 90hem) Hemingway B. S. (1990) Thermodynamic properties for bunsenite, NiO, magnetite, Fe3O4, and hematite, Fe2O3, with comments on selected oxygen buffer reactions. American Mineralogist 75(7-8), 781-790. 37.990 (Ref.: 90hem) Hemingway B. S. (1990) Thermodynamic properties for bunsenite, NiO, magnetite, Fe3O4, and hematite, Fe2O3, with comments on selected oxygen buffer reactions. American Mineralogist 75(7-8), 781-790. 45.01 (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.
29.80 63.73 -3.38 (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

Bunsenite + 2H+ ⇌ Ni+2 + H2O

298.15 K, 1 bar log10K: 12.51 ΔH°r:-106030 J·mol-1 (Ref.: 90hem) Hemingway B. S. (1990) Thermodynamic properties for bunsenite, NiO, magnetite, Fe3O4, and hematite, Fe2O3, with comments on selected oxygen buffer reactions. American Mineralogist 75(7-8), 781-790.
T(°C) 0 25 60 100 150 200 250 300
log10K 14.20 12.51 10.55 8.76 6.98 5.54 4.31 3.21
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-344.587545 -0.054042 23408.881240 123.612351 -993782.644885