Page 16 - Curriculum Visions Dynamic Book

Processing the raw materials
Fortunately, much of the raw material for ceramics
is readily available and needs fairly little treatment before it can be used. This is in marked contrast to most industries (in the case of metals, for example, the metal has to be extracted from its ore before it can be used) and helps keep down costs.
One of the side effects of using the material straight from the ground is that it provides the opportunities for many attractive regional variations. In bricks and roof tiles, for example, the changing colours between regions reflect the changes in the natural iron staining that occurs on the clays.
Furthermore, natural clays already contain sand and flux, and so they fire easily.
Bricks and tiles are coloured. Most tableware is not. Clay dug from the ground may not be suitable for it. Special sources of clay, such as kaolinite (china clay) deposits, must be found. As a result, ceramics intended to have a white colour (and sometimes called “whiteware”) tend to be made in more restricted locations, and factories are often grouped near a suitable source of material.
In other cases each of the raw materials has to be washed to get rid of staining and impurities.
(Above and below) The colour of both bricks and mortar depends on the materials from which they were made. In general, the more iron
in them, the stronger the colour. This wall is made from a recycled collection of bricks that show the great range of colours that can be obtained.
The brickwork below is from a completely different region than the one above. In this case the bricks are dominated by purple colours.
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