UNARY SYSTEMS
Systems which can be defined by a single component are called Unary Systems.
In this system pressures from 0 to 15 kbars seven phases, each with the same compostion - H2O have been recognized:
- Ice I
- Ice II
- Ice III
- Ice IV
- Ice V
- Water
- Steam
SiO2 System
In the one component SiO2 system in the temperature range from 0 to 2,000°C and a pressure range from 0 to 30 kbars six phases of SiO2 are recognized. At pressures > 30 kbar a seventh phase, stishovite, exists.
The six phases of SiO2 are:
- coesite
- alpha quartz (Trigonal)
- beta quartz (hexagonal)
- tridymite
- cristobalite
- anhydrous melt
