Anorthoclase is a mineral that belongs to the plagioclase feldspar group. It is a complex mineral that is rich in potassium and sodium. There are several synonyms for Anorthoclase, which include: alkali feldspar, orthoclase, sanidine, and microcline. Orthoclase is the most common synonym for Anorthoclase. Sanidine is a high-temperature form of Anorthoclase that is found in volcanic rocks. Microcline is a type of Anorthoclase that is found in igneous rocks. Alkali feldspar is a group of minerals that includes Anorthoclase and other feldspar minerals that contain potassium and sodium. These synonyms are often used interchangeably in scientific literature and geology.