Glass article

To develop a noble glass composition which is based on a known potassium-zinc crystal glass composition suitable for chemical strengthening, in which most of contained ZnO component is replaced with a combination of far inexpensive other oxides, which is easily to melt in a tank and to form by machine into table wares, which satisfies the legal conditions as crystal glass specified in glass composition, refractive index, and density, and which is superior in chemical strengthening suitability; and to provide a chemical strengthened crystal glass article which has high practical strength as a table ware and can be subjected to washing with an alkali. [Solving Means] The following glass composition gives a chemical strengthened luxury crystal glass article which has a material cost cut in one half as compared with that of the known chemical-strengthening-suitable potassium-zinc crystal glass composition and which shows higher practical strength and proportionally less deterioration: SiO2 in a content of more th