9.Ferro Frit 3221 M.P./°F 1450 Silica/Alumina ratio: 3.8:1 Equivalent Molecular Weight: 398.967 Molecular Formula of Ferro Frit 3221: K2O 0.175 Al2O3 0.691 SiO2 2.610 Na2O 0.812 B2O3 1.501 CaO 0.013 Percentage Analysis 39.29 % SiO2 17.66 % Al2O3 4.13 % K2O 12.61 % Na2O 0.18 % CaO 26.12 % B2O3 _____________________ 100 % TOTAL Comments: 9.4 x 10-6 coefficient of expansion (50-450° C)