Class: Silicates
Group: Feldspar
Original description: ‘Mikroklin’ Breithaupt, J. F. A., 1830. Ueber die Felsite und einige deue Specien ihres Geschlechts — Journal für Chemie und Physik 60: 324—327 [
view in ‘Library’].
Type locality: Arendal, Aust-Agder; Stavern, Larvik, Vestfold, Norway.
Type material: unknown.
Etymology: from the Greek for little and inclined, for the small deviation of the cleavage planes from 90°.
Distribution: Australia; Brazil: Minas Gerais; Canada: at Bancroft, Ontario; Italy; Madagascar; Namibia; Norway: Arendal and Larvik; Russia: Kola Peninsula and Urals; Switzerland; USA (
Anthony et al., 2001—2005).
Chemistry
KAlSi3O8
Essential elements: oxygen (O), aluminium (Al), silicon (Si), potassium (K).
Crystal data
Crystallography: triclinic — pinacoidal.
Crystal habit: prismatic crystals elongated along [001] or [100], perhaps the largest of any species, to 50 m; granular, massive.
Twinning: Carlsbad, Baveno, and Manebach laws very common; polysynthetic twinning on the Albite and Pericline laws give an orthogonal grid pattern on (001) (
Anthony et al., 2001—2005).
Material from ‘Repository’