Formula : K(AlSi3)O8

Space group: 
Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m
Dana class: (76) Tectosilicate Al-Si Framework (76.1) with Al-Si frameworks (76.1.1)K (Na,Ba) feldspars
High temperature: 
The stability of this mineral depends on substitution (fluorine) and pressure, the stability domain ranges between around 400C to 1600C
Geological context: 
High sanidine forms a series with high albite. Most common in felsic volcanic and hypabyssal rocks as rhyolites, phonolites, trachytes; as spherulites in volcanic glass. Also from ultrapotassic mafic, high-temperature contact metamorphic (sanidinite facies), and hydrothermally altered rocks. From eclogite nodules in kimberlite.

Dernière mise à jour le 25.01.2021


T(°C) 0 25 60 100 150 200 250 300
log10K 1.42 0.62 -0.54 -1.70 -2.91 -3.93 -4.88 -5.85