NaCaAlSiO

NaCaAlSiO is not a mineral name but a shorthand notation for a mixed alkali calcium aluminosilicate composition that can occur in framework silicates. In this class, aluminum and silicon occupy tetrahedral sites in a three-dimensional silicate framework, with Na+ and Ca2+ balancing the negative charge created by aluminum substitution for silicon. The composition can be viewed as a feldspar-like solid solution between albite NaAlSi3O8 and anorthite CaAl2Si2O8, commonly represented as Na_(1−x)Ca_xAl_(1+x)Si_(3−x)O8 where x ranges from 0 to 1. This emphasizes that the Na-Ca distribution controls the unit cell parameters and physical properties.

Occurrence and usage: In geology, plagioclase feldspar within igneous and metamorphic rocks embodies this Na–Ca–Al–Si–O framework; in materials science, engineered aluminosilicate glasses and ceramics exploit similar compositions for ion-exchange, durability, and thermal stability. Because NaCaAlSiO is not a fixed chemical formula, its exact properties vary widely with cation distribution and ordering, and real materials will have additional cations and non-stoichiometry.

Related topics include plagioclase feldspars, aluminosilicate minerals, and zeolites.