Clay

Have you wanted to work with clay or wondered what is made from? Well, I have decided to do a tutorial on clay and how to work with it. This is the first installation about clay. I am starting with the explanation of the formation and types of clay.

I hope you find this interesting and informative. I will be adding sections to this blog as I finish them. In the meantime, if you have any questions or comments, please send them to me.

CLAY

Clay is a naturally occurring material composed primarily of fine-grained minerals, which show plasticity through a variable range of water content, and which can be hardened when dried or fired, according to Wikipedia. The clay that is used in pottery is weathered, decomposed granite and consists mainly of alumina and silica.

Different types of clay, when used with different minerals and firing conditions, are used to produce earthenware, stoneware, and porcelain. One of the earliest artifacts is a drinking vessel made of sun-dried clay used in prehistoric times. Clay tablets were used as the first writing medium inscribed with a blunt reed called a stylus.

Kaolin clay is considered primary clay, and it is found at the original source of formation. It is in a protected area shielded from the elements. It is white in color and the main component of porcelain clay. All other clays have been moved from the original location by water and the elements, collecting impurities., such as other minerals, including iron, and other organic materials.

Stoneware clay has grog added to it and is plastic for formation. Grog is fired clay that has been broken and crushed. When fired stoneware is gray or pale pastel in color. A glaze is usually added then fired for color.

Red earthenware clay has high iron content. It is very plastic and usually smoother to work with that the stoneware clay. When fired it has a red color called terra cotta.