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Mineral speciesFormula
 AmesiteMg4Al2(Al2Si2)O10(OH)8 
Mineralogy
Family: Chlorite Group 
Space group: Triclinic - Pedial H-M Symbol (1) Space Group: C1 
Dana class: 7.1.2c.1 (71) Phyllosilicate Sheets of Six-Membered Rings (71.1) with 1:1 layers(71.1.2c)Serpentine group (Amesite subgroup) 
Geological context
High temperature: Based on the chlorite s.l., chlorite may be stable from about 100C to 600C and more with the increase of the pressure. 
Geological context: A product of low-grade metamorphism of Al, Mg-rich rocks. 
Thermodynamics
Individual properties
Molar weight: 557.370 g/mol  ΔGºf-8,365,841 J/mol ref.  Sº: 403.20 J/mol/K ref. 
  ΔHºf-9,035,900 J/mol ref.  Cp: 516.34 J/mol/K ref. 
Reaction properties
Chemical reaction:  Amesite + 20H+ = 4Al+3 + 4Mg+2 + 2H4SiO4 + 10H2O 
log10(Keq) = A + B.T + C.T-1 + D.log10(T) + E.T−2 (with T expressed in Kelvin)
A B C D E
 -3.47883121e+3   -5.49834120e-1   2.16225700e+5   1.24995821e+3   -9.42280032e+6 
Van t'Hoff
@ 25°C, 1 bar: log 10(Keq)69.40
ΔH°r-766,388 J/mol ref.
T (ºC) : 0 25 60 100 150 200 250 300
log 10(Keq):  81.69   69.40   55.33   42.55   29.88   19.55   10.60   2.33 
Maier Kelley
Cp(T) = a + b*10-3T + C*105T-2 (with T expressed in Kelvin)  ref.
a:631.95 J/mol/K 
b:282.68 J/mol/K2 
c:-177.69 J.K/mol 

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