Mosaics are made of tesserae, pieces of cut stone or glass. By the Roman and Byzantine periods, an empire-wide trade existed for luxurious materials, such as marble and granite, which were used in their creation. Click on the image above to see a mosaicist from the Chicago Mosaic School demonstrating the materials needed for making mosaics.
Click on the image above to see master mosaicist from the Chicago Mosaic School demonstrating the art of mosaic making by recreating a section of the Art Institute of Chicago's giraffe mosaic.
Roman floor mosaic, late 2nd-early 3rd century A.D., El Djem, Tunisia. ©iStockphoto.com/Allen Tobey
The earliest examples of pavement mosaics, such as this one, have been found in Tunisia and date from the 5th to the 3rd century B.C. Across the Roman Empire, mosaics were very similar in technique and imagery, especially after the 1st century B.C., when the empire began to expand into North Africa (Morocco and Libya) and the Levant (including modern Syria, Jordan, Lebanon, Israel and Cyprus). Romans who dispersed into the provinces demanded the creature comforts of Rome. Roman floor mosaics can be found as far north as England.
Detail of Christ Pantokrater from the Deesis, Mosaic, 1261, in Hagia Sophia, 532-537, Istanbul, Turkey ©iStockphoto.com/Nikada
While early Byzantine mosaics in homes followed the Roman technique, many Byzantine mosaics were made with glass tesserae in a glittering array of colors, and these were imported from across the empire. A hallmark of the Byzantine mosaic technique is the lavish use of gold tesserae, wherein each individual tile sandwiched gold leaf between two glass sheets. Because glass tesserae were delicate, they were used to decorate only the walls and ceilings of sacred spaces.