Celadonite

Formula : K(MgAl)Si4O10(OH)2

Family: 
Pyroxenes
Space group: 
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Dana class: 
71.2.2a.6 (71) Phyllosilicate Sheets of Six-Membered Rings,(71.2)with 2:1 Layers (71.2.2a)Mica Group (Muscovite subgroup)
High temperature: 
It is a low temperature mineral.
Geological context: 
Replaces primary ferromagnesian silicate minerals in altered intermediate to mafic volcanic rocks, developed under low-grade zeolite facies metamorphism; as amygdule fillings in basalts or andesites.

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
396.736 139.680 (Ref.: 02par/vid) Parra, T., Vidal, O., and Agard, P., 2002, A thermodynamic model for fe-mg dioctahedral k white micas using data from phase-equilibrium experiments and natural pelitic assemblages: Contribution to Mineralogy and Petrology, v. 143, p. 706-732. -5455644 (Ref.: Internal calculation) -5834736 (Ref.: 02par/vid) Parra, T., Vidal, O., and Agard, P., 2002, A thermodynamic model for fe-mg dioctahedral k white micas using data from phase-equilibrium experiments and natural pelitic assemblages: Contribution to Mineralogy and Petrology, v. 143, p. 706-732. 291.000 (Ref.: 02par/vid) Parra, T., Vidal, O., and Agard, P., 2002, A thermodynamic model for fe-mg dioctahedral k white micas using data from phase-equilibrium experiments and natural pelitic assemblages: Contribution to Mineralogy and Petrology, v. 143, p. 706-732. 325.75 (Ref.: 98hol/pow) Holland T.J.B., and Powell R., 1998. An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16, p. 309 343.
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.
357.08 205.51 -82.32 (Ref.: 98hol/pow) Holland T.J.B., and Powell R., 1998. An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16, p. 309 343.
Reaction properties

Celadonite + 6H+ + 4H2O ⇌ Al+3 + K+ + Mg+2

298.15 K, 1 bar log10K: 10.22 ΔH°r:-114928 J·mol-1 (Ref.: 02par/vid) Parra, T., Vidal, O., and Agard, P., 2002, A thermodynamic model for fe-mg dioctahedral k white micas using data from phase-equilibrium experiments and natural pelitic assemblages: Contribution to Mineralogy and Petrology, v. 143, p. 706-732.
T(°C) 0 25 60 100 150 200 250 300
log10K 11.90 10.22 8.00 5.89 3.77 2.03 0.47 -1.08
log10K(T) = A + B·T + C·T-1 + D·log10(T) + E·T−2 (T in Kelvin)
A B C D E
-2295.159655 -0.307490 142884.409123 814.893216 -8763195.434973