Six rows of vertical facets decorate this small Roman glass beaker or drinking vessel. Faceted cut glass and colorless glass became popular between 50 and 100 A.D. Both types represented a change in glass technology. The creation of a facet-cut vessel involved two artisans. A glassblower would first create a hollow, thick-walled blank of colorless glass. To produce colorless glass, the glassblower had to add de-coloring agents to change the glass's natural light greenish color. A glasscutter then took the blank and fashioned the vessel on a lathe. The production of faceted glass may have begun in the eastern Mediterranean, perhaps in Egypt. Colorless, faceted glass vessels may have initially been created to imitate more expensive rock crystal vessels, but they soon become desired items of tableware in their own right. Although this beaker is a simple example of the glasscutter's art, elaborate diatreta , or cut-glass vessels, were among the most precious luxury objects in the Roman world.