Lead-free glasses

An article of crystal glassware in which the glass is essentially free from lead, that exhibits a density of at least 2.70 g/cm3, a liquidus below 1000° C., and a long viscosity curve, a coefficient of thermal expansion in the range 70-110×10−7/° C., good scratch resistance and chemical durability, and that has a composition, expressed in terms of weight percent on an oxide basis of:

• SiO2 52-66 ZnO 15-30 Al2O3 0-4 BaO 0-7 Li2O 0-4 MgO + CaO + SrO 0-5 Na2O 3-16 ZrO2 0-4 K2O 0-12 B2O3 0-4.

A laminated, glass article comprising two glass components joined directly to each other, one component being a glass that is essentially free of lead, that exhibits a density of at least 2.70 g/cm3, a liquidus below 1000° C., and a long viscosity-temperature curve, a coefficient of thermal expansion in the range 70-110×10−7/° C., good scratch resistance and chemical durability, and that has a composition, expressed in terms of weight percent on an oxide basis of:

• SiO2 52-66 ZnO 15-30 Al2O3 0-4 BaO 0-7 Li2O 0-4 MgO + CaO + SrO 0-5 Na2O 3-16 ZrO2 0-4 K2O 0-12 B2O3 0-4,
• the other component being a glass having a different composition, but having a long viscosity-temperature curve that closely matches that of the first glass over the entire temperature range.