Ceramic - Pottery Dictionary

by Susan Mussi




Clay is a naturally occurring material taken out of the ground and is composed primarily of fine-grained materials formed by the decomposition of granite and the gradual chemical weathering of rocks. Clay is made up of different materials that form different types of clay bodies which vary in maturing temperatures, strength and color of the clay and the bisque when fired.

Clay deposits are mostly composed of clay minerals which show plasticity through a variable range of water content and which can be hardened when dried or fired.

Clay has plasticity when mixed with water and when dry, it becomes firm and when fired permanent physical and chemical reactions occur which cause the clay to be converted into a ceramic material. It becomes solid, not pliable, breakable and still absorbs water but this does not make the shape changeable.

Different types of clay are mixed with different minerals and fired using different methods to produce earthenware, stoneware and porcelain. Depending on the content of the soil, clay can appear in various colors, from a dull grey to a deep orange-red and is used for making pottery items, both practical and decorative, all of which have to be fired with a glaze to make them non absorbent to water.

Note: The sections CLAY 1 to 6 are the first stages of preparing clay for working and throwing. They are linked, click here Clay (1) Kneading to go to the first. These are followed by two files Clay (7) Accessories and Clay (8) Tools. The next are sections on preparing and working with clay and are not linked to each other. The first is Clay: (a) Bodies. it is better to go into C and move down, there are 16 sections.

The next section; Clay (1) Kneading