An important building material of individual blocks of clay or mud, some with tempering of sand or straw. Bricks, which are not always rectangular, may be baked in a kiln to terra cotta or sun-dried - which is referred to as mud-brick or adobe. The chief building material throughout the Near East has always been mud-brick. Bricks can be used as dating criteria, especially when they bear stamped inscriptions. Decorative glazed bricks first appeared in Assyrian times, as at Ishtar Gate in Babylon.