These shapes may account for the slipperiness of wet clay and its ability to cling together and be molded. Depending mainly on the kind and amount of impurities present, there are many varieties of clay, each with its own special uses. Fire clay, which will not melt or crumble at extremely high temperatures, is used to make the brick linings for industrial furnaces and those huge ladles that carry molten metal. Another kind goes into stoneware, such as bean pots, casseroles, and hard clay products like roofing tile, sewer pipe and face brick. Ordinary brick, drail tile, building tile and pottery are made from some of our most common clays.
Porcelain is baked from a highly purified form of white clay called kaolin.
Surprisingly, clay also is used in phonograph records, medicines, cosmetics, crayons, pencils, tooth powder, soaps, paper, textiles and water softeners. Illinois is rich in underground wealth. As a mineral producer it ranks first among the states of the Upper Mississippi Valley, fifth in the nation, and exceeds all but a half dozen countries of the world. Of course, in money value, coal and oil are most important but, in our state, clay and clay products come third with an annual value of about fifty million dollars, More important than any money value of clay products is the clay in Illinois soils. The right amount of clay, mixed with coarser particles and organic matter forms the loams that make this the bread basket of the country.