Clay is very fine particles of dirt, which float in streams and rivers and then sink to the bottom. They stick together, and remain in clumps, coating riverbanks and beds.
Some of the earliest people to exploit clay deposits were the Egyptians and Sumerians.
They build many things from clay, which were found many hundreds of years later, still mostly preserved and very beautiful.
The great thing about clay is that it is so cheap, and since in its natural form it is very squishy and wet, it can be shaped into anything and then left in the sun to dry and harden.
If you want to make it soft again, to make something else, or to improve your design, all you need to do is to soak it in water again.
To harden the clay products so that even water cannot soften it, it is put in a clay oven (kiln) which bakes the moist clay. This process is called firing.
This is an age-old tradition that dates back to about 6000 BC, yet practiced in many parts of the world today, especially as a form of art.
In the ancient world, man built houses out of clay too, they would mix straw with the clay so it would stick together, and these bricks were called mud-bricks.
Other than that, they made dishes, plats, cooking pots, statues, drinking cups, roof tiles, and many other things.
Natural clay has many other natural minerals in them, called clay minerals, which also contain bits of metal oxides.
There are different types of clay, such as ceramics and porcelains, which are made from clay being mixed with various other compounds.
Earthenware clay products come in many colours, and stoneware clays are usually grey and are also strong to work with like earthenware products.
The clay pottery industry is found to flourish in mostly the non-industrialized nations and provide a valuable source of income for people.