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 before being cooled with water. This process prevents the iron in the clay from fully oxidizing, resulting in better 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%.仿古青砖 are replicas of various styles of ancient blue bricks, produced using the same firing method and clay material as the ancient blue bricks, but with modern techniques.