an imitation of paintings by setting bits of colored stone or glass together in a surface. This form of decoration was carried to great perfection by the Greeks and Romans. It was used to form floors and pavements and to adorn walls and ceilings. One Roman artist boasted that he could produce on glass cubes 15,000 varying shades and tints. Another brought into a face of Paul V 1,700,000 bits of colored glass, the largest of which was less than a millet seed. See POMPEII; MOSAIC.