Original paper
Melting of spessartine at high pressure
Mottana, A.
Neues Jahrbuch für Mineralogie - Monatshefte Jg. 1974 Heft 6 (1974), p. 256 - 271
46 references
published: Aug 27, 1974
DOI: 10.1127/njmm/1974/1974/256a
ArtNo. ESP156197406002, Price: 19.00 €
Abstract
The melting behaviour of spessartine has been investigated at pressures from 8 to 32 kilobars, using a piston-cylinder apparatus and an internally heated pressure vessel. As at atmospheric pressure, spessartine melts congruently over the entire pressure range along a curve represented by the equation: T (°C) = 1213.5 + 14.875 P (kb) that, after correction for the pressure dependence of the thermocouple e.m.f., becomes: T(°C) = 1205 + 16.5 P (kb). The melting behaviour is strongly influenced by the humidity conditions of the sample: at 24 kb the atmospheric dampness lowers the beginning of melting by some 80° C, possibly changing the melting behaviour to incongruent. The physical properties of spessartine synthesized at high pressure are: a0 = 11.617 ± 0.003 Å, nD = 1.799 ± 0.003.
Keywords
Experiment • spessartine • melting • high pressure (8—32 kb)