The Roman glass pitcher stands 14 inches high. Age has given it a shimmering multicolored patina. Romans were expert glassmakers. They used various molding techniques until the first century B.C., when glass-blowing technology became widespread. Roman glass came in all colors, thanks to impurities in the sand or deliberately added chemicals such as antimony (opaque white), copper (greenish blues and reds) and manganese (pinks and purples). Clear glass was the most expensive variety.