If you're a potter or a ceramist, have you asked what pottery is made of? Pottery is made of many ingredients with the main part as clay. There are many parts such as organic material, water and metal oxides. Depending on the types, there may be phyllosilicate minerals.
Types of Pottery Clay
There are three types of clay, and they are kaolin, earthenware and stoneware. Between 6,000 to 4,000 BC, potter’s wheel was first introduced in Mesopotamia. This revolution gave man in the past a way to produce things out of clay. Potters no longer had to use the long process of the hand molding method to shape clay. They were able to have more freedom in their art.
Pottery has always looked good, but the process has changed a lot with the emergence of the pottery wheel. Instead of working on a target art, they are now working on an art object. The earliest artefacts known to archaeologists are usually handcrafted, undecorated and unglazed clay vessels, but around 6000 BC, various artefacts were developed in regions such as the Middle East, China, and Europe.
From beautiful paintings depicting the history of royal kings to magnificent bowls and plates and beautiful animals, the pot wheel design has provided potters with ingenuity and skill never seen before.
What is pottery clay and how did the earth create it?
Over time (hundreds of years), rocks on the surface of Earth's atmosphere have formed microscopic particles. This deterioration is due to weathering and chemicals such as carbonic acid. The silicate rocks eventually break down into sediments, which slowly combine to form clay.Few of the clay remains at the place of its formation, maintaining its purity. The closer the clay is to the source, the purer it is. This clay is heavy, dense and bright in color. However, at other times, clay can be transported from place to place by water or air.
As a result, it accumulates debris along the way and ends up with new sedimentary substances. These clays are less durable due to the presence of impurities that form during the process.
Thus, clays are divided into two groups, primary and secondary, depending on how they form the sediment. The first clay deposits settle at the formation site, while the secondary clay settles far from the formation.
How pottery clay is manufactured?
For maximum usage, clay must go through manufacturing. First, clay soils were harvested on the site. This is accomplished by digging topsoil and gravel into the ground up to 24m. The more excavation depth, the purer the clay. When excavated, the fresh clay has a moisture content of about 22%. They usually clump together, but can easily break down into small pieces that can be turned into solid material.
The clay was then placed in a location without walls and air dried. Then the clay is visually analyzed for color and consistency to divide the clay into several types. However, a more in-depth chemical content analysis is done after a few loads to ensure consistent results. This chemical analysis allows the clay to be classified according to the purpose for which it can be used.
The clay is then sent to a rotating tank where the clay cracks into small pieces. The clay is subsequently placed in an oven by a method called flash-drain. This heating reduces the moisture content by 1 to 2%. Then the dry clay is crushed into a fine powder. A different mixture of clays to create a unique product. The different types of clay are powdered clay.
Then a purification process to remove physical and chemical impurities is carried out. During this time, the clay is clean, dry and crushed. Tests should confirm the purity of the clay. This includes checking the colors to make sure they are the correct shade. Once the purity is verified, the clay is packaged and delivered to the seller of the dish.
Pottery clay can be purchased as a powder and recycled. Alternatively, you can buy it wet.
What is the variety of pottery clay?
In the case of ceramics, different types of clay have different uses depending on their physical and chemical properties. These include composition, workability, porosity, and cooking temperature. As mentioned earlier, many types of clay contain large amounts of water, organic matter, and metal oxides. The difference between these ingredients defines their product.
Therefore, some porcelain clays are suitable for certain types of ceramics. So if you are making pottery wares, it's a good idea to ask yourself, "What is pottery clay made of?" before starting to work.
The three types of pottery clay
Earthenware is the most common type of clay. There is also evidence that it was used by potters from the Neolithic Age. Earthenware is a type of clay containing iron and mineral impurities. Due to impurities, the ripening temperature is low, such as 1745F to 2012F. The physical composition of earthenware is 15% feldspar, 35% quartz, 25% kaolin and 25% clay.
This type of porcelain paste is a very good plastic, which makes it sticky and easy to work with. Earthenware is generally available in "quality" colors such as red, orange and yellow, and some are light gray. When fired, the mineral composition and the type of electrons determine the color reaction. The most popular earthenware is terracotta, which means "baked earth".This type of porcelain clay is ideal for making non-flammable tiles, terracotta pots and pots.
Shortly after the earthenware was discovered, stoneware was found along with the clay. Its name suggests its rock-like properties, as it is the strongest and most durable of all porcelain clays. The ceramics are made from coarse grains and are hotter and cooler than utensils.
Aging temperature is categorized based on average cooking temperature and average cooking temperature between 2150F and 2260F and high cooking ranges between 2200F and 2336F.
It is very stable with little or no water absorption (non-porous) after fire. The formula for modern sandstone generally revolves around 15% quartz, 30% feldspar and chamotte or grogg, 15% clay. Additionally, as the second type of clay, limestone has high levels of iron and other impurities. These ingredients are generally available in shades of pale yellow, gray, and dark brown. Due to its strength and performance, stoneware is durable and can be used as utensils and cookware. Coffee and tea cups are best brewed as they store and distribute heat evenly.
Kaolin, also known as porcelain, is the purest of the three types of porcelain. It is rich in silica and has a moderate pH. Due to the absence of impurities, kaolin does not have many colors. It is only available in bright colors like white. Therefore, kaolin is also called white clay. When wet, kaolin turns very light gray. When baking, colors vary from light gray or pale yellow to almost white. Kaolin is not plastic like earthenware and stoneware, so it is the least functional of us. Free of impurities, it has a maximum ignition temperature of approximately 3272F. Kaolin can therefore be difficult to work with. Kaolin is usually mixed with other clays to improve workability and reduce heat and cold. For example, kaolin is mixed with clay to make dishes. However, kaolin is often used in cosmetics and is very important in some skin care products.
Choosing the best clay
The first step in choosing the perfect clay to work with is understanding what the clay is made of. Before making a decision, you need to know what is in the different types of clay. The differences in composition affect the properties, function and fire properties of different types of porcelain clay, as mentioned in the article. So with the tools you have and the goals you want to achieve, you want to use clay that is easy to work with. For example, if your goal is to make coffee mugs, stoneware may be the best choice. This is because it contains ingredients that increase durability. Store the heat and distribute the heat evenly.
If you want to make porcelain, kaolin is the right clay. Keep in mind that kaolin should be mixed with other clays to improve performance and reduce unhealthy temperatures. If you are a beginner or want to learn tableware as a hobby, pottery is for you. Indeed, earthenware contains a lot of plastic, so it is easy to work.
Other elements to take into account when choosing a clay
Clay powder or ready-to-use clay? You can buy dry or wet clay. It is a full-fledged mixed enterprise, because wet clay is more expensive than dry clay. However, mixing clay is a bit of an art form. So, as a beginner, it is better to buy clay prepared in advance until you have gained some experience. Be aware of temperature: many types of pottery clay have varying degrees of aging. This means that the oven used must reach a certain temperature.