Glass mosaic ribbed bowl fragment late 1st century B.C.-early 1st century A.D. Roman Body fragment.Translucent cobalt blue and opaque white.Convex curving side, tapering downward.Mosaic pattern formed from sections of a single cane in blue ground with large white spiral threads; on exterior, part of a broad vertical rib with rounded profile.Polished interior; pitting of surface bubbles on interior; dulling, pitting, and iridescent weathering on exterior and jagged edges.. Glass mosaic ribbed bowl fragment. Roman. late 1st century B.C.-early 1st century A.D.. Glass; cast and tooled. Early Imperial. Glass