Feldspar is the name applied to aluminum silicates that contains alkaline or alkaline earth elements in the composition. Depending on the element present in the mineral structure it receives specific names, the most common being: Orthoclase  (when it has potassium), Albite (when it has sodium) and Anorthite (when it has calcium).

The Feldspars are used as sources of fluxes (K₂O, Na₂O and CaO) and alumina (Al₂O₃) for most industrial applications, and they also provide the ceramic glaze transparency or opacity to obtain the beauty of the various colors.