It is believed that mosaics originated some 4,000 years ago, although no one is sure of who first got the idea of painting with stone. By the 18th century A.D., builders (or artists) were using small colored stones to create patterns in pebble pavements. These were typically just unstructured decoration.
The Greeks seem to have been responsible for raising the creation of mosaics to a true art form with their precise geometric patterns and depictions of people and animals. Rather than restrict themselves to the use of naturally occurring pebbles, they began to cut small stone cubes, or tesserae.
These allowed more precise patterns and a greater variety of colors and tints. Tesserae that were only a few millimeters big allowed the mosaic to truly imitate the detail found in paintings. The cut surface also made the finished product more even. It could then be ground smooth, waxed, and polished.
In fact it goes on to state that, "Pavements of this type have been found by the hundred thousand in buildings of the Roman period from northern Britain to Libya, from the Atlantic coast to the Syrian desert."
With the decline of the Roman empire and the rise of the Byzantine empire around the 5th century A.D., mosaics took on new characteristics. They began to reflect Eastern stylistic influences and the use of glass tesserae called 'smalti'. These were cut from thick sheets of colored glass and often backed by silver or gold leaf.
Since the smalti were ungrouted, light was able to reflect freely from the metal leaf backing, as well as refract within the glass. While the Romans had primarily used mosaics for floors, the Byzantines used them to cover ceilings and walls, often setting the pieces of glass at different angles so that the light was caught in different ways.
In contrast, the mosaics produced in the Islamic world were predominantly geometric or mathematical patterns. In fact, an article in the Journal Science said that some of these resemble a type of crystalline pattern demonstrated by a mathematician and cosmologist back in the early 1970s.
According to the article, by the 15th century, Islamic artists had developed techniques "to construct nearly perfect quasi-crystalline Penrose patterns, five centuries before their discovery in the West."
They are also used for tables and garden stepping-stones. Rather than detract from the artistic prestige of mosaics, these applications are in keeping with their humble beginning as a functional flooring material that also looked nice.
Ultimately, the value of art depends, not on the medium used or the object adorned, but on the skill of the artist. This becomes even more important when you're painting with stone.