Clay is one of the most ancient and necessary materials for man. They made dishes, building materials from it, used in cosmetics, medicine and other industries. But what is clay, really? How does its structure affect its properties? The answers to these questions are inside the clay, but until the middle of the 20th century, no one could look into it.
Clay is a fine-grained sedimentary rock that is dense when dry and plastic when wet. It has been known to man since ancient times and was one of the first building materials. But until the middle of the 20th century, clay was classified only by utilitarian properties, such as color, density, plasticity, sintering temperature, and ability to swell in water. Chemical analysis also did not give a complete answer to questions about its structure.
However, in the 50s. XX century, it became possible to look inside the clay thanks to the spread of x-ray machines. The x-ray beam passes through the crystal lattice of the mineral and forms a “picture” on the detector, similar to the one we see on x-rays of fractures. For each mineral, such a “picture” will be unique, and it helps to find out its crystalline features, internal defects, and many other properties.
X-rays helped to reveal the essence of clay and understand its structure. Clay is made up of particles smaller than 2-3 microns in size, and they are extremely tightly adhered to each other. Its base is always aluminosilicate, but other chemical elements show high variability even within the same clay deposit. This explains the differences in the utility properties of clays and their ability to be used in different industries.
Today, clay is used in many industries, from construction to cosmetics. Its properties and structure continue to be studied by scientists from all over the world. For example, researchers in France and the US recently discovered that clay could be used to create electrodes for lithium-ion batteries, which could lead to more efficient and environmentally friendly batteries.
Thus, clay is not only an ancient and necessary material for humans, but also an object of study for scientists who continue to uncover its secrets and find new areas of application.