What is mosaic? It is a type of decorative art built by joining small units of material covering a certain surface to create models and visual images or geometric patterns, panoramas, animals, images, flowers etc. These small stone pieces are called 'tesserae' a roman word which means cubes. The word mosaic originates from Greek meaning small stones. In Hebrew we use the word mosaic for the artwork of pictures of models made with small stones or glass cubes. The art of mosaic is an old one and an artistic-cultural tradition which developed in the Mediterranean basin in early times, approximately the 3rd century B.C. and which was apparent mainly in the internal halls of public buildings and private homes, on walls or floors. This art was mainly developed by the Greek, especially on Crete, from where it reached the Roman Empire. The major development of this art was during the Byzantine period, mainly during the reign of King Constantine who built the churches in Jerusalem. This art was also adopted by mosques all around the Mediterranean, as well as in synagogues in Israel. The main reason for using this mosaic technique was that in seeking a strong and cheap coating for the floor, they found that natural river pebbles in a base of cement solves this problem satisfactorily. About 500 B.C. the floors of the homes of the rich in Greece and Asia Minor (then settled by the Greek) were decorated with marble, and those of regular people were decorated with floors made of pebble mosaic. From the 7th or 8th centuries B.C. people started using black and white pebbles, making simple patterns. Later they added natural, unprocessed stones in other colors like yellow, green and red. Approximately since 400 B.C we find many pictures from these stones. Later they began processing these stones and creating small cubes, from which the picture was made. At that time, around the 2nd century B.C. they began manufacturing small glass cubes used mainly for floor decoration. It may be assumed that the first mosaic layers were simply buildings, part of whose job was laying river pebbles. In time this task developed and became art.
(Courtesy of Wikipedia).