Argutite(beta)

Formula : GeO2

Family: 
Oxides
Space group: 
Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 4/mnm
Dana class: 
4.4.1.7 (4) Simple Oxides (4.4) with a cation charge of 4+ (A++++ O2) (4.4.1)Rutile group (Tetragonal: P4/mnm)
High temperature: 
High temperature mineral.
Geological context: 
In a zinc deposit formed in metamorphosed lower Paleozoic sediments.

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
104.609 -504320 (Ref.: Internal calculation) 52.09 (Ref.: 98pok/sch) Pokrovski G.S. and Schott J., 1998. Thermodynamic properties of aqueous Ge(IV) hydroxide complexes from 25 to 350C: Implications for the behavior of germanium and the Ge/Si ratio in hydrothermal fluids. Geochimica et Cosmochimica Acta, 62, 1631-1642
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.
61.18 13.79 -11.74 (Ref.: 98pok/sch) Pokrovski G.S. and Schott J., 1998. Thermodynamic properties of aqueous Ge(IV) hydroxide complexes from 25 to 350C: Implications for the behavior of germanium and the Ge/Si ratio in hydrothermal fluids. Geochimica et Cosmochimica Acta, 62, 1631-1642
Reaction properties

Argutite(beta) + 2H2O ⇌ Ge(OH)4

298.15 K, 1 bar log10K: -1.97 ΔH°r: J·mol-1 (Ref.: )
T(°C) 0 25 60 100 150 200 250 300
log10K -2.16 -1.97 -1.75 -1.54 -1.30 -1.11 -0.94 -0.81
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-148.196361 -0.019095 7920.906316 52.947428 -503747.976009