Unlike the technique of glassblowing, in which a blob of molten glass is made hollow by blowing into it through a tube, lampworking involves heating small rods of colored glass over a lamp or torch, then shaping the glass with handheld tools. It is used to make glass beads, paperweights, and other small items. The practice developed in Italy during the Renaissance, and in later centuries was used to produce popular trinkets in France. Fumes from vaporized gold can give the glass what color? Discuss