Western Europe has made more use of brick than any other area in the world. After the Great Fire of London in 1666 the whole city transformed from being a city of wood to one of brick, solely to avoid the risk of fire. Manufacturing Raw Material Technology has come to the assistance of modern day brickmakers, allowing them to utilise many different raw materials. Clays used in brickmaking can be grouped into three categories. The differences are in the amount of minerals that are present in the clay.
Surface clays Typically from river bottoms.
Shale clays Under intense geological pressure varying from slate to rock. Fireclays Found deeper underground and requiring mining. All clays are extracted using conventional mining techniques. Blending is nearly always carried out to obtain uniform consistency which may include crushing of slate or rock. Preparation All clays need to be mixed with water, the amount of which depends on the nature of the clay and its plasticity.