Formula : SiO2

Space group: 
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c
Dana class: (75) Tectosilicate Si Tetrahedral Frameworks(75.1) SiO2 with [4] coordinated Si (75.1.4) Dana Group
High temperature: 
Coesite is a high presure mineral its stability is limited by stishovite (an other silica polymorph) at about 65 kbar.
Geological context: 
Formed at pressures in excess of 20 kbar, as fine-grained intergrowths with quartz and silica glass in impact metamorphosed rocks and tektites. A primary phase in grospydite (kyanite-garnet-clinopyroxene) xenoliths in kimberlite, and intergrown with quartz as inclusions in garnet and clinopyroxene within eclogites of high-grade metamorphic terranes.

Dernière mise à jour le 25.01.2021


T(°C) 0 25 60 100 150 200 250 300
log10K -3.26 -2.91 -2.59 -2.32 -2.06 -1.85 -1.68 -1.55