Original description: ‘Anorthit’ Rose, G., 1823. Ueber den Feldspath, Albit, Labrador und Anorthit — Annalen der Physik und der Physikalischen Chemie 73: 186—194 [
view in ‘Library’].
Type locality: Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy.
Type material: unknown.
Etymology: from the Greek
αν (an) and
oρθός (orthos), ‘not right angle’ or ‘oblique’, in allusion to the oblique triclinic form of the crystals.
Canada; Italy: Monte Somma and Vesuvius, Campania; Japan; Russia: Urals; Sweden; USA (