kaoliniitin

Kaoliniitti is a clay mineral, specifically a phyllosilicate. Its chemical formula is Al2Si2O5(OH)4. It is one of the most common minerals on Earth and is a primary constituent of kaolin, also known as china clay. Kaoliniitti is typically white or off-white in color and is soft and earthy in texture. It forms through the weathering of aluminum-rich silicate minerals, such as feldspar, in humid environments. The process involves the breakdown of these parent minerals by chemical reactions, primarily hydrolysis, leading to the formation of kaoliniitti. It is also found in hydrothermal alteration zones.

The crystal structure of kaoliniitti consists of layers of silica tetrahedra and alumina octahedra. Each layer is held together by relatively weak van der Waals forces, which contributes to its softness and plasticity when wet. This plasticity, along with its white color and inertness, makes kaoliniitti highly useful in various industrial applications. It is extensively used in the production of ceramics, paper, paints, rubber, and plastics. In ceramics, it provides plasticity for shaping and contributes to the fired strength and whiteness of the final product. In the paper industry, it is used as a filler and coating to improve brightness, opacity, and printability. Kaoliniitti also finds applications in cosmetics, pharmaceuticals, and as an absorbent material.