Clay is a mixture of minerals formed by the mechanical, chemical, and organic decomposition of feldspathic rocks. It is most often found in layers close to the earth’s surface. In folk tradition, it is said that clay has ten or even a hundred “hands”. When clay is exposed to high temperatures, the clay particles fuse together. This process is called sintering. In this way, ceramics are created: solid, waterproof, resistant to temperature variations, and able to withstand direct exposure to fire.