Sarooj
Sarooj is a traditional water-resistant mortar used in Iranian architecture, used in the construction of bridges, and ice pits or earth refrigerators.
It is made of clay and limestone mixed in a six-to-four ratio to make a stiff mix, and kneaded for two days. A portion of furnace slags from baths are combined with cattail fibers, egg, and straw, and fixed, then beaten with a wooden stick for even mixing. Egg whites can be used as a water reducer as needed.
