Potassium feldspar
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/6/66/PotassiumFeldsparUSGOV.jpg/220px-PotassiumFeldsparUSGOV.jpg)
Potassium feldspar refers to a number of minerals in the feldspar group, and containing potassium:
- Orthoclase (endmember formula KAlSi3O8), an important tectosilicate mineral that forms igneous rock
- Microcline, chemically the same as orthoclase, but with a different crystalline structure
- Sanidine, the high-temperature form of potassium feldspar (K,Na)(Si,Al)4O8
- Adularia, a more ordered low-temperature variety of orthoclase or partially disordered microcline
- Amazonite (sometimes called "Amazon stone"), a green variety of microcline