Recognition Study of Materials and Techniques Construction Decorative Sassanian Mosaics (Bishapour Palace)

Abstract
The mosaic art as a decorative element in buildings enjoys several thousand years of age in Egypt, Mesopotamia, Greece, Rome and Byzantium and is widely usedbut technically speaking, the earliest mosaic forms have poorly made. They were made by insertion of fruit cores or broken pottery pieces in the wet mud mortar of walls. Later, the art evolved rapidly and extensively used for architectural decoration, especially in the Greek and Roman civilizations.  Mosaic Art, reached its zenith in Byzantine period. In the ancient Iranian architecture, mosaic art has been rarely used in buildings, and the only discovered one is in the Bishapūr Palace dating back to the Sasanian Empire. In 1935, Professor Ghirshman discovered a piece of decorative mosaic on the floor of Bishapūr Palace. They was made of small pieces of colored stones. The mosaics images include portraits of Sasanian princes or dancing and or musician women. This research is a laboratory study for identification of materials and technique that was employed in making of Bishapūr mosaics. It also compared the techniques and materials of Bishapūr mosaic with the Roman mosaic art. Laboratory results obtained from this study and at the same time, the identified materials and technique of the Sasanian mosaics were compared with the similar Roman ones. At the beginning, the site where the mosaics were unearthed in Bishapūr was studied. And at site, we sampled from the remaining pieces of stone mosaics as well as mortar of the mosaics. Samples were studied and tested through petrography and SEM analysis. The result of petrography and SEM analysis showed that the mortar used in mosaics of Bishapūr, is lime mortar. Lime mortar was used in making mosaics because they were laid down in the yard and open space. The very same mortar has been used for outdoor spaces (including bathroom and yard) in mosaic works in Greece and Rome. However, Iranian architects were highly skilled in making lime mortars it was widely used in  construction of bridges. In addition, these tastes revealed that the stones used for Bishapūr mosaic are limestone. Consequently, the study findings proved that materials used in Bishapūr mosaics are  similar to the Roman mosaics. it is noteworthy that the designs of Bishapūr mosaics are completely rooted in the Iranian painting design. Hence, perhaps mosaics were made in Bishapūr through Roman techniques by the Iranian artisans. As we can see similar depictions on Sasanian silver mares (including   Raytheon and dishes) There exists another theory that the mosaic makers were Roman as such mosaics were disappeared in later periods due to return to their homeland These tasting also showed that the type of mosaic stones is limestone. The study results showed that material used in Bishapour mosaic is the similar to the Rome mosaic. But the designs of Bishapur mosaics are completely Iranian painting design, Because Most of them, special women pictures, are same the picture of silver object from Sassanid period that some of that show in this article. finally, With result of this studies, is the possibility to Reconstruction of mosaic with technique of Sassanid