Feldspar is a mineral which gives the ceramic masses a greater sintering with less porosity, a greater mechanical resistance and a reduction of temperature during the firing cycle. When used in ceramic linings, it provides a greater impermeability, a greater surface quality and a greater performance of color development. When used in glasses, it reduces the melting point, increases removal, reduces viscosity, reduces the formation of pits or bubbles and increases chemical resistance. This mineral input is increasingly being used as a source of alkali, boosting the vitrification process in lower temperatures with a substantial reduction of the consumption of energetic inputs.