noun
- A calcium aluminum silicate mineral, CaAl₂Si₂O₈, that is the calcium-rich end member of the plagioclase feldspar series.
Usage: technical; mineralogy
Examples
- Anorthite is commonly found in igneous rocks such as basalt and gabbro.
- The plagioclase feldspar series ranges from anorthite to albite.
- Geologists identified anorthite crystals in the lunar samples brought back by the Apollo missions.
- Anorthite has a triclinic crystal structure and typically appears white or gray in color.
- The composition of anorthite makes it an important indicator of rock formation conditions.