Stone artifacts and stonemasonry
Traditionally, stone-based arts in Iran have been of enormous diversity. They include items such as stone architecture, stone tools and equipments, reliefs, stone volumes and sculptures, stone stamps, stone frames, tombstone, stone mosaics, stone ornamental works, cutting jewelry and precious and semi-precious stones, stone beads and lithography. Stones are one of the most basic materials used by the man to make tools and shelters and meet his needs. Ancient Stone Age and Paleolithic periods represent periods when stoned took precedence over metal and other materials. Remains of stone-built houses in northern Iran date back to 7,000 years ago. In stone buildings, rubble stones have been used along with gypsum and lime mortars. Due to their weight and difficulty of application, rubble stones have relatively been replaced by construction materials such as bricks. However, in spite of being heavy and difficult to carry or extract, rubble stones have preserved their position in construction of heavy and hard buildings such as bridges, tunnels, avalanche barriers, separating walls and stone decorations