White_pipe_clay
White pipe clay (Dutch: pijpaarde) is a white-firing clay of the sort that is used to make tobacco smoking pipes, which tended to be treated as disposable objects. This suited pipeclay, which is not very strong.
Such clays are not uncommon; in England they are found in the river Thames upstream from London, and in the Low Countries the clay was found in deposits of the Rhine and Meuse rivers and in the 16th-century centres of production for white pipe clay objects were Cologne, Utrecht, Liège and Gouda, South Holland. The name comes from the most common usage of white pipe clay, tobacco pipes.