Formula : Mg3Si4O10(OH)2
Family:
Space group:
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Dana class:
71.2.1.3 (71) Phyllosilicate Sheets of Six-Membered Rings (71.2)with 2:1 Layers (71.2.1)Pyrophyllite-talc group
High temperature:
The temperature stability range of talc is large from room-temperature to around 700C. It depends on the chemistry of rock, the water fugacity, the CO2 fugacity, of the pressure.
Geological context:
In talc-rich schists or steatite through hydrothermal alteration of mafic rocks (steatitization) subsequent to serpentinization during greenschist facies metamorphism. Also formed by thermal low-temperature metamorphism of siliceous dolostones.
Dernière mise à jour le 25.01.2021