TY - JOUR
T1 - Experimental investigation of andradite and hedenbergite equilibria employing the hydrogen sensor technique, with revised estimates of ΔfG0 m,298 for andradite and hedenbergite
AU - Moecher, D. P.
AU - Chou, I. M.
PY - 1990
Y1 - 1990
N2 - Hydrothermal experiments were carried out at 2 kbar, 600-860°C to resolve discrepancies among previous studies on fO2-T stability relations for the following equilibria: 1) andradite (And) = hematite (Hm) + wollastonite (Wo), 2) And = magnetite (Mt) + Wo + O2, 3) And + quartz (Qz) = hedenbergite (Hd) + Wo + O2, and 4) And + Mt + Qz = Hd + O2. A variety of O buffer and H2 generation techniques were used to access a wide range of fO2-T conditions. The results yielded an internally consistent set of experiments on andradite and hedenbergite stability. The ΔfG0 m,298 for andradite and hedenbergite calculated from the data are -5428.0 ± 5.9 and =2676.6 ± 5.3 kJ/mol, respectively. -from Authors
AB - Hydrothermal experiments were carried out at 2 kbar, 600-860°C to resolve discrepancies among previous studies on fO2-T stability relations for the following equilibria: 1) andradite (And) = hematite (Hm) + wollastonite (Wo), 2) And = magnetite (Mt) + Wo + O2, 3) And + quartz (Qz) = hedenbergite (Hd) + Wo + O2, and 4) And + Mt + Qz = Hd + O2. A variety of O buffer and H2 generation techniques were used to access a wide range of fO2-T conditions. The results yielded an internally consistent set of experiments on andradite and hedenbergite stability. The ΔfG0 m,298 for andradite and hedenbergite calculated from the data are -5428.0 ± 5.9 and =2676.6 ± 5.3 kJ/mol, respectively. -from Authors
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M3 - Article
AN - SCOPUS:0025626011
SN - 0003-004X
VL - 75
SP - 1327
EP - 1341
JO - American Mineralogist
JF - American Mineralogist
IS - 11-12
ER -