The glasses of this system can be obtained from cheap and readily available raw materials--sand, kaolin, dolomite, and chalk. In addition, they have a number of extremely valuable properties a they do not contain alkali metal oxides. In the work described in this section, the authors have studied the effect of P2O5, TiO2, ZrSiO4, Cr2O3, and fluorine additives on the physicochemical properties of a glass which lies in the lowest melting region of the SiO2-Al2O3-MgO-CaO system, and of two glasses that have the same MgO and CaO molar content. Author
Unedited rough draft trans. of mono. Sintez Stekol i Silikatnykh Materialov (Synthesis of Glasses and Silicate Material), n.p., 1963 p28-32.