INTRODUCTION

Naturally available clay is used directly or in the processed form to make tiles and ceramic materials apart from making bricks.

Tiles are thin slabs made out of brick earth by moulding and then burning them. The best clay for tile making is generally found a few metres below the brick earth. Tiles have been used for roofs, floors, walls, etc.

Ceramics is the term used for the act of making objects with a special type of clay. This term is derived from the Greek word keramos meaning potter’s earth. Clay for ceramics is the product of chemical weathering of various types of rocks. Orthoclase feldspar is mainly responsible for the production of clays in nature. This mineral forms kaolinite during decomposition. Kaolin, a product having the composition of pure kaolinite, is fine white clay required to manufacture some ceramic articles.

Apart from bricks and tiles, other objects which are made using various types of clays and techniques are discussed below.

Earthenware is the term used for clay products burnt at low temperature. They have coarse surfaces and are opaque. General cooking vessels usually used in villages fall under this group.

Stoneware is a product of refractory clay, ground stone and pottery. These are burnt at high temperatures to vitrification. Stoneware jars are of great use. Earthenware and stoneware are together known as pottery.

Porcelain is a white translucent ceramic material of kaolin and feldspar. The objects are produced by firing at a very high temperature. Most crockery are made of porcelain and are glazed.

Terracotta is a hard brownish unglazed vitrified ceramic material used for ornamental purposes.