Formula : NaAl2(AlSi3)O10(OH)2

Space group: 
Monoclinic Space Group: C 2/c,Cc
Dana class: 
71.2.2a.2 (71) Phyllosilicate Sheets of Six-Membered Rings(71.2)with 2:1 Layers(71.2.2a) Mica Group (Muscovite subgroup)
High temperature: 
The stability range of paragonite is very large from 260C C in hydrothemal systems up to 750C with the pressure increase. The chemistry of the sediments plays a role on the stability of this mineral.
Geological context: 
Uncommon, but may be in large amounts, in low- to medium-grade metamorphic schists and phyllites, in muscovite-biotite gneisses, quartz veins, fine-grained sediments, and glaucophane-bearing rocks. It is also present as alteration of primary minerals in hydrothermal halo.

Dernière mise à jour le 25.01.2021


Individual properties (298.15 K)
T(°C) 0 25 60 100 150 200 250 300
log10K 21.39 16.80 11.28 6.12 0.91 -3.42 -7.27 -10.93