Primary clays are those that have formed in the same place where they are found, which means that they have not been transported by water or wind. This process of formation at the place of origin gives them a high purity, as they contain few impurities or secondary minerals that are usually transported by natural forces. As a result, primary clays have a more uniform texture and less variability in composition compared to secondary clays.
A prominent characteristic of primary clays is their low plasticity, due to the lack of impurities that increase the modeling ability of secondary clays. This low plasticity makes primary clays less suitable for hand or wheel modeling without the addition of other materials, but makes them especially valuable in certain types of ceramic production that require a more stable and resistant material.
The purity of primary clays makes them a fundamental material in the manufacture of high quality ceramic products, such as fine porcelain. In particular, kaolin is a classic example of a primary clay, widely used in the production of porcelain.
The use of primary clays is crucial in the creation of ceramic products that require exceptional temperature resistance, such as fine tableware, decorative figurines and other objects that must maintain their shape and durability after being subjected to high temperatures in the kiln. Thanks to their high thermal resistance and ability to maintain structure during the firing process, primary clays are the preferred choice in the manufacture of quality porcelain and other luxury ceramic items.
Interesting Fact
Primary clays tend to be lighter in color due to the absence of impurities such as iron, making them valuable for ceramics that require a clean, bright finish.
Helpful Tip
If you are looking for a clay with low plasticity but high temperature resistance, opt for a primary clay and compensate for its lack of plasticity by mixing it with other types of clay.
