Item talk:Q162580
From geokb
Mindat Short Description
Mica Group.
An uncommon Na-member of the mica group. Occurs in low- to medium-grade metamorphic schists and phyllites, in muscovite-biotite gneisses, quartz veins, fine-grained sediments, and glaucophane-bearing rocks.
2M^1; 3A polytypes.
Geoscience Ontology Status Notes
Schaffhüutl C (1843) Chemisch-mineralogische Untersuchungen: Untersuchung einiger talkartigen Mineralien. Paragonit, Annalen der Chemie und Pharmacie, Heidelberg 46, 325-347
IMA Formula (from Mindat)
NaAl2(Si3Al)O10(OH)2
RRUFF Formula (from Geoscience Ontology)
NaAl2(Si3Al)O10(OH)2
