Clay minerals are tiny, naturally occurring particles found in soil and rocks. They are formed from the weathering of larger minerals and are essential for many environmental processes. These minerals have a unique structure that allows them to hold water and nutrients, making them crucial for plant growth. There are several types of clay minerals, including kaolinite, montmorillonite, and illite. Each type has different properties and uses. For example, montmorillonite is known for its ability to expand when wet, which is useful in applications like drilling mud and cat litter. Overall, clay minerals play a vital role in our ecosystem.