| 摘要 |
<p>This invention relates to a crystal glass having a refractive index higher than 1.53 and a high mechanical strength, free of any content of compounds of lead, barium and arsenic and guaranteeing maximum safety for health, which consists in that it comprises by weight: 55-70% SiO2, 0.05-3.5% Li2O, 2-15% Na2O, more than 3% and less than 5% or more than 15% and less than 19% K2O, 5 to 10% CaO, more than 1% and less than 4% or more than 7% and less than 8% ZnO, 0.1-3.5% B2O3, 0.1-3.5% Al2O3, 0.1-3.5% TiO2, less than 3.5% ZrO2, 0.05-1.5% Gd2O,3 0.05-1% P2O5, 0.1-1% Sb2O3.</p> |
