In the Zaffiro jewelry design studio— located a short stroll from their 1913 Craftsman home in the Hawthorne neighborhood of Portland, OR— Jack and Elizabeth Gualtieri carry forward the artistic legacy of ancient Etruscans. The technique, called granulation, is a decorative process that consists of applying miniature spheres of gold(or, in its modern adaptation, platinum) to a similar surface and then heating the entire piece to a temperature high enough to form a permanent bond between the surface and the spheres.  If the spheres are over-fired they’ll melt onto the surface; if under-fired, they won't adhere properly.