Premium
PT‐diagram of the system SiO 2 ‐H 2 O
Author(s) -
Ostrovsky I. A.
Publication year - 1966
Publication title -
geological journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.721
H-Index - 54
eISSN - 1099-1034
pISSN - 0072-1050
DOI - 10.1002/gj.3350050110
Subject(s) - tridymite , cristobalite , diagram , quartz , phase diagram , triple point , thermodynamics , mineralogy , materials science , chemistry , physics , metallurgy , mathematics , statistics , organic chemistry , phase (matter)
The high‐temperature and medium‐pressure part of the PT‐diagram of the system SiO 2 ‐H 2 O has been investigated experimentally. The equilibrium diagram is discussed in the light of Schreinemakers general theory of PT‐diagrams. The triple invariant point cristobalite + tridymite + quartz lies at 1190°C and 1430 atm. Neither cristobalite nor tridymite are stable at high pressure. Quartz may precipitate from the melt at a very high temperature (1360°C and higher), if the pressure is great enough, and if the water content is low. Using new experimental and published data a PT‐diagram of the system SiO 2 ‐H 2 O in the large PT‐region is given.