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7626738 
Journal Article 
Diamond crystallization in fluid and carbonate-fluid systems under mantle P-T conditions: 1. Fluid composition 
Sokol, AG; Pal'yanov, YN; Pal'yanova, GA; Tomilenko, AA; , 
2004 
Yes 
Geochemistry International
ISSN: 0016-7029 
MAIK NAUKA/INTERPERIODICA/SPRINGER 
NEW YORK 
42 
9 
830-838 
English 
WOS:000224285800003 
Graphite and a fluid-generating substance (silver oxalate, oxalic acid, or anthracene) were sealed in a platinum or a gold capsule and run for a long time at elevated pressure (5.7 GPa) and temperature (1200 or 1420degreesC). Both the starting materials and gases released from the capsule after the experiment were analyzed by gas chromatography. The results of the thermodynamic modeling of C-O-H fluid at 5.7 GPa and 1200-1500degreesC and at 7 GPa and 1300-1900degreesC were evaluated. The composition of the fluid generated by the decomposition of real substances was calculated. The experimental and calculated data show that the composition of CO2 and H2O-CO2 fluids changed considerably during the long-term diamond crystallization experiments in the C-O-H system. The compositions of water and methane-hydrogen fluids are more stable. The compositional changes of the H2O-CO2 and H2O fluids with increasing temperature from 1200 to 1420degreesC indicate a decrease in hydrogen fugacity in the material of the high-pressure cell surrounding the experimental capsules.