Anorthoclase Mineral Data

General Anorthoclase Information
Chemical Formula:	(Na,K)AlSi3O8
Composition:	Molecular Weight = 266.25 gm
	Potassium 3.67 % K 4.42 % K₂O
	Sodium 6.48 % Na 8.73 % Na₂O
	Aluminum 10.13 % Al 19.15 % Al₂O₃
	Silicon 31.65 % Si 67.70 % SiO₂
	Oxygen 48.07 % O
	______ ______
	100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:	Na_0.75K_0.25AlSi₃O₈
Environment:	In high-temperature sodic volcanic and hypabyssal rocks.
IMA Status:	Valid Species (Pre-IMA) 1885
Locality:	Rather abundant worldwide. Some localities for well-characterized material include: on Pantelleria and Ustica Islands, Italy. At Larvik, Norway. From Berkum, North Rhine-Westphalia, Ge Link to MinDat.org Location Data.
Name Origin:	From the Greek for "oblique" and "fracture," descriptive of the cleavage
Name Pronunciation:	Anorthoclase + Pronunciation
Synonym:	ICSD 31180
	PDF 9-478
	Soda Microcline