About the preservation of mosaics

Mosaics from whatever time period or location always have a lot to tell about customs, religion, and simple daily life, and as such are very valuable testimonies of our past. 

Yet, as soon as the precious tesserae are exposed, the question arises about what to do with the mosaic and about the best way to preserve it. 

The problem was first confronted during the 18^th century when sites like Pompeii and Herculaneum were excavated. In those days, archaeology was not established as a proper science and most of the finds were carried away to be displayed in the mansions of the rich and famous. As a result, the mosaics were taken apart and the most pleasing pictures were framed in simple or elaborate frames. 

As the number of excavations steadily grew in the 19^th and 20^th centuries, archaeology matured equally and it became clear that not all mosaics – and certainly not the larger ones – could be moved for conservation inside a museum. 

Another option was to rebury the mosaics. To this purpose and probably by trial and error, different materials such as soil, gravel, or sand were used to cover the mosaics. The most obvious material was the soil, which was readily available at the excavation site. Besides, it made sense to rebury the mosaics using the same material that had contributed to their survival for many centuries. Nowadays, sand and gravel with or without plastic netting are often implemented all over antique sites. 

I often regret that I cannot actually have a look at those hidden treasures although I totally understand the logic behind this decision. However, standing at the entrance of the Royal Palace in Aegae and not being able to see the large round mosaic of the Tholos or Sanctuary is rather frustrating. In other places, like in Dion, Greece, (see: Dion, the Macedonian Sanctuary), strolling among the remains of Roman houses is not as rewarding as it could be if the many floors were exposed. 

At times, in order to help the visitor visualize the wealth of the mosaics in situ, shelters have been built to protect the precious stones under all circumstances. There are many such cases, such as Pella, Greece, or Nea Paphos in Cyprus. 

In the end, it all depends on the circumstances and the locations where the mosaics are discovered. In Zeugma, Turkey, (see: Zeugma, Border-town along the Euphrates River) even larger floors were removed from the site because the old city was to be flooded after the construction of a dam on the Euphrates. The only way to save what could be saved was to remove the mosaics and shelter them in a newly constructed museum in Gaziantep. 

Mosaic floors that belong to extensive villas are nowadays generally kept intact. A good example is the huge Villa of Piazza Armerina in Sicily (best known for the pictures of the bikini-girls) which has been largely roofed. On other occasions, the entire basement of the villa is cleared and made accessible underground as is the case in Ravenna, Italy. This site, called Tapeti di Pietra (carpets of stone) had been discovered during the construction of a parking lot underneath a modern building. Another similar situation occurred in Antakya, Turkey (see: Antakya’s rich collection of mosaics) where the heavily undulating mosaic floor will be incorporated into the hotel that is under construction. 

It appears that there are many options to safeguard a mosaic floor, all depending on the location and the circumstances in which they are found. Overall, the best and safest conservation choice is the reburial technique. However, this has to be done very carefully and the site must be kept under surveillance. It is sad to find mosaics disintegrating because the layer of sand and gravel is not thick enough and curious or malicious visitors scratch the protection away to expose the mosaics underneath. Many archaeological sites in the Middle East and North Africa are being damaged beyond repair like in Ptolemais, Libya (see: Ptolemais, heritage of the Ptolemies in the Cyrenaica).