What is clay?
Clay is essentially a mineral resource that is very widespread globally and consists of tiny particles visible only under a microscope - clay minerals. These particles have a flat shape and, due to the electrical tensile forces between the particles, they are very tightly attached, as a result, the clay is very malleable and sticky.
How is clay obtained?
As clay is a mineral, it must be mined to obtain it. In order to get large quantities, clay is quarried using excavators and dumpers. A shovel and trolley are also sufficient for smaller amounts. The clay is usually located close to the surface and is easy to extract, so there is no need to use complex technological equipment or blasting.
There are two methods for using clay extracted for the production of building materials.
Method 1: The extracted clay is dried and later ground to obtain a clay powder. To do this, the clay is dried naturally in the sun or industrially with gas and then ground into a powder in a special mill.
Method 2: The extracted clay is placed in moist clay baths where it is soaked and mixed into a liquid. The result is either clay milk or clay cream, ready to use, as required.
Clay is mined in a few places in Estonia, as there are still quite a few industries that use clay today. The primary clay deposits are located in Northern Estonia (Kunda, Aseri, and Kallavere clay deposits) and in Southern Estonia (Joosu, Arumetsa, and Küllatova clay deposits).
Where is clay used?
Clay has been used for thousands of years and has a long history. Clay, for example, was one of the first building materials that man began to use. The temple Ramasseum in Egypt, built in 1304-1207 BC, is an archaeological site of Mari in Syria, dating back to 2900 BC. The Tabo Monastery in India is built in 996 BC is the oldest surviving clay building. In addition to building materials, clay has historically been used in ceramics, where the 27,000-year-old ceramic culture Věstonice Venus has been found.
Clay is still used today as a building and finishing material, such as clay plaster and clay bricks, and due to its unique construction physical properties, clay is becoming popular again.
In addition to building materials, clay is used successfully in healthcare because it has been proven to have the ability to absorb toxic substances and toxins. In healthcare, clay is used externally, as a compress on the skin, and internally, collecting toxic substances and microbes in the intestines and stomach and expelling them from the body.
Clay is also very widely used in cosmetics. Toothpaste is one such everyday cosmetic product that uses clay. Also, every woman has probably used or heard the term "clay mask" at least once in her life. Clay is also used in many other natural cosmetics, such as soaps, powders, exfoliating creams, wraps. It is known that clay was used for cosmetic purposes in ancient times when creams and masks were applied as a compress to the face and body. There are about 40 types of clay in total, and the most popular is white clay, kaolin, which is widely used in the cosmetics and healthcare industries. – kaoliin, mida kosmeetika- ja tervishoiutööstuses laialdaselt kasutatakse.
Clay is successfully used in art therapy and ceramics. Due to the plasticity and formability of clay, it has no definite boundaries and shapes, and rules. Thus, it is possible to observe and analyze a person and his behavior when working with clay. One form of clay therapy is, for example, clay therapy called "Working in a clay field." This method was developed in the 1970s and is used successfully in psychiatry, trauma therapy, and rehabilitation. This therapy uses soft clay, a wooden box, a little water, and, of course, a therapist who observes and guides through the clay's creative process and sends the client.
Clay has very special properties
Clay is one of the most similar materials to living matter, so it has many unique properties that cannot be ignored. These properties are divided into two camps: the physical and the healing. In these areas, the special properties of clay are best expressed.
The physical properties of the building are evident in the construction and finishing of the house. The essential building physical properties of clay are reflected in the indoor climate and air quality: a sufficient amount of clay can regulate humidity, keeping it stable near 50%. Clay also has a scientifically proven ability to clean the air - just as plants are able to clean the air, so can clay. As a result of these two properties, the clay is antibacterial, antistatic, inhibits the formation of mold, and neutralizes bad odors and harmful substances. Using clay as a building material has another special effect - clay preserves the wood, which means that the clay keeps the wood dry, which is a prerequisite for the long-term preservation of the wood.
The healing properties of clay are the reason why it is used in healthcare and cosmetics. As already mentioned, the healing effect is its ability to absorb toxic and other harmful substances that the body does not need. This property has been proven by a laboratory experiment ("Saviravi", publishing house Sünnimaa, 2001). In cosmetic products, clay has the following properties: binds free radicals, contains large amounts of vital minerals (over 56 different), antibacterial (containing radium).
Impact of clay use on the environment
Builders who use clay in their daily work claim that clay is the building material of the future. We also confirm this statement! There is more than one reason for this, but the main one is that clay mining and processing has a small ecological footprint:
- Clay is a local material and can be found in almost every corner of the world. By using local clay, we save on transport costs in terms of both nature and money.
- Clay production requires little energy. Simple technology is used for both mining and processing.
- Production does not generate hazardous waste.
- Clay buildings have a long history, as evidenced by a number of historical and archaeological finds.
- Clay is recyclable and compostable: we take it from the ground and return it to the ground. It can be said that we borrow clay. We don't have to grow it or cut it like wood to use it.
The philosophical side of clay
Here we quote Rene Pere's thoughts from the book "Curd paint and clay plaster":
"Reflections on clay actually lead us to the question of why clay was created at all. Maybe to help a person and create more decent living conditions for him? If the clay is older than us, perhaps it is also smarter than us and teaches itself to use itself more purposefully? According to some myths, mud and clay were also used to make the first person, who was then given a soul. Since then, man, in turn, has tried to breathe soul into the clay, giving it shape and putting it to life. In any case, the message of the clay plaster that has been passed on to us is that, as humans, it is a living organism that is constantly changing and whose immersion in the depths of nature is like an endless journey of discovery."
What is clay? http://eestiloodus.horisont.ee/artikkel3364_3333.html
Researchers statement: https://www.sciencedaily.com/releases/2013/11/131105132027.htm
Clay treatment: https://maarohud.weebly.com/savi.html
Clay as a mineral resource - https://maapou.keskkonnaharidus.ee/Eesti-maapoue-aarete-infokaardid.pdf
Clay Handbook - https://dspace.emu.ee/xmlui/handle/10492/3761
Clay in cosmetics - https://buduaar.tv3.ee/nao-ja-kehahooldus/savi-ime-loodusest-enesest/
“Curd paint and clay plaster” - Rene Pere