Adobe bricks are a type of fired brick, with the main raw material for ancient blue bricks being clay. After the clay is mixed with water, it is extruded into shape and then fired in a kiln at approximately 1000 degrees Celsius. The bricks are then cooled with water to prevent the iron in the clay from fully oxidizing, enhancing their resistance to weathering and water. Tests show that ancient blue bricks have a compressive strength greater than 10 MPa and a water absorption rate less than 20%. Replica ancient blue bricks are made by mimicking the styles of ancient blue bricks, following the same firing methods, and using the same clay material as the ancient blue bricks, but produced with modern techniques.