An easy one for today....a wiki explanation of what??
X is a natural building material made from sand, clay, water, and some kind of fibrous or organic material (sticks, straw, and/or manure), which the builders shape into bricks using frames and dry in the sun. X buildings are similar to cob and mud brick buildings. X structures are extremely durable, and account for some of the oldest existing buildings in the world. In hot climates, compared with wooden buildings, X buildings offer significant advantages due to their greater thermal mass, but they are known to be particularly susceptible to earthquake damage.