Tremolite: new enthalpy and entropy data from a phase equilibrium study of the reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O

Mark D. Welch; A. R. Pawley

Tremolite: new enthalpy and entropy data from a phase equilibrium study of the reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H₂O

University of Edinburgh

Research output: Contribution to journal › Article › peer-review

Abstract

New enthalpy and entropy data have been obtained for a natural end-member tremolite from phase equilibrium experiments on the above high temperature dehydration reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H₂O. Six reversed experimental brackets were obtained at 0.25 kbar (996-1033 k), 0.6 kbar (1038-1058 K), 1 kbar (1075-1104 K), 1.5 kbar (1101-1125 K), 2 kbar (1115-1128 K), and 8 kbar (1179-1209 K), from which the enthalpy of formation and the third-law entropy of tremolite have been calculated. The values obtained are ΔH_f ⁰(Tr) = -12299.48 ± 14.84 kJ/mol and S⁰(Tr) = 0.5525 ± 0.0100 kJ/mol.K. The new thermodynamic data is used to calculate revised limits of tremolite stability in the system CaO-MgO-SiO₂-H₂O (CMSH). -from Authors

Original language	English
Pages (from-to)	1931-1939
Number of pages	9
Journal	American Mineralogist
Volume	76
Issue number	11-12
Publication status	Published - 1 Jan 1991

Cite this

@article{8241cdba2e804047aefec01b108e4d18,

title = "Tremolite: new enthalpy and entropy data from a phase equilibrium study of the reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O",

abstract = "New enthalpy and entropy data have been obtained for a natural end-member tremolite from phase equilibrium experiments on the above high temperature dehydration reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O. Six reversed experimental brackets were obtained at 0.25 kbar (996-1033 k), 0.6 kbar (1038-1058 K), 1 kbar (1075-1104 K), 1.5 kbar (1101-1125 K), 2 kbar (1115-1128 K), and 8 kbar (1179-1209 K), from which the enthalpy of formation and the third-law entropy of tremolite have been calculated. The values obtained are ΔHf 0(Tr) = -12299.48 ± 14.84 kJ/mol and S0(Tr) = 0.5525 ± 0.0100 kJ/mol.K. The new thermodynamic data is used to calculate revised limits of tremolite stability in the system CaO-MgO-SiO2-H2O (CMSH). -from Authors",

author = "Welch, {Mark D.} and Pawley, {A. R.}",

year = "1991",

month = jan,

day = "1",

language = "English",

volume = "76",

pages = "1931--1939",

journal = "American Mineralogist",

issn = "0003-004X",

publisher = "de Gruyter, Walter GmbH & Co",

number = "11-12",

}

TY - JOUR

T1 - Tremolite

T2 - new enthalpy and entropy data from a phase equilibrium study of the reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O

AU - Welch, Mark D.

AU - Pawley, A. R.

PY - 1991/1/1

Y1 - 1991/1/1

N2 - New enthalpy and entropy data have been obtained for a natural end-member tremolite from phase equilibrium experiments on the above high temperature dehydration reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O. Six reversed experimental brackets were obtained at 0.25 kbar (996-1033 k), 0.6 kbar (1038-1058 K), 1 kbar (1075-1104 K), 1.5 kbar (1101-1125 K), 2 kbar (1115-1128 K), and 8 kbar (1179-1209 K), from which the enthalpy of formation and the third-law entropy of tremolite have been calculated. The values obtained are ΔHf 0(Tr) = -12299.48 ± 14.84 kJ/mol and S0(Tr) = 0.5525 ± 0.0100 kJ/mol.K. The new thermodynamic data is used to calculate revised limits of tremolite stability in the system CaO-MgO-SiO2-H2O (CMSH). -from Authors

AB - New enthalpy and entropy data have been obtained for a natural end-member tremolite from phase equilibrium experiments on the above high temperature dehydration reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H2O. Six reversed experimental brackets were obtained at 0.25 kbar (996-1033 k), 0.6 kbar (1038-1058 K), 1 kbar (1075-1104 K), 1.5 kbar (1101-1125 K), 2 kbar (1115-1128 K), and 8 kbar (1179-1209 K), from which the enthalpy of formation and the third-law entropy of tremolite have been calculated. The values obtained are ΔHf 0(Tr) = -12299.48 ± 14.84 kJ/mol and S0(Tr) = 0.5525 ± 0.0100 kJ/mol.K. The new thermodynamic data is used to calculate revised limits of tremolite stability in the system CaO-MgO-SiO2-H2O (CMSH). -from Authors

UR - http://www.scopus.com/inward/record.url?scp=0026282706&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0026282706

SN - 0003-004X

VL - 76

SP - 1931

EP - 1939

JO - American Mineralogist

JF - American Mineralogist

IS - 11-12

ER -

Tremolite: new enthalpy and entropy data from a phase equilibrium study of the reaction tremolite = 2 diopside + 1.5 orthoenstatite + β-quartz + H₂O

Abstract

Other files and links

Fingerprint

Cite this