Corkite

Formula : PbFe3(PO4)(OH)6SO4

Family: 
Phosphates
Space group: 
Trigonal - Ditrigonal Pyramidal HM symbol (3m) Space Group: R 3m
Dana class: 
43.4.1.2VII - 43 Compound Phosphates, etc. ; 43.4 Compound Phosphates, etc. (Anhydrous Compound Anions With Hydroxyl or Halogen) ; 43.4.1
High temperature: 
low temperature
Geological context: 
An uncommon, low-temperature, secondary mineral occurring in the oxidized zones of hydrothermal base-metal deposits.

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
667.820 151.100 (Ref.: 63wyc) Wyckoff, R.W.G., 1963, Crystal Structures, Second edition, tome 4, Interscience Publishers, New York, p. 320-322. -3388203 (Ref.: 84nri) Nriagu J.O., 1984, Formation and stability of base metal phosphates in soils and sediments, Chap. 10. In: Phosphate Minerals, J.O. Nriagu and P.B. Moore (Eds), Springer-Verlag, ISBN 3-540-12757-7, 318-329
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.
Reaction properties

Corkite + 8H+ ⇌ 3Fe+3 + H2PO4- + Pb+2 + SO4-2

298.15 K, 1 bar log10K: -1.94 ΔH°r: J·mol-1 (Ref.: )
T(°C) 0 25 60 100 150 200 250 300
log10K -1.94 -1.94 -1.94 -1.94 -1.94 -1.94 -1.94 -1.94
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-1.943259 0.000000 0.000000 0.000000 0.000000