What type of particles are classified as smaller than 0.002 mm?

Particles classified as smaller than 0.002 mm are categorized as clay. Clay particles are characterized by their very small size, which allows them to adhere to one another and retain water better than larger particles. This fine size contributes to the unique properties of clay, such as its plasticity when wet and its compactness when dry.

In soil science, understanding the classification of different soil particles is essential because it affects soil behavior, drainage capabilities, nutrient retention, and plant growth. The classification system typically includes sand, silt, and clay, with clay being the finest and smallest of these particles.

The other categories, such as sand and gravel, consist of significantly larger particles. Sand ranges from 0.02 mm to 2 mm, while gravel consists of particles larger than 2 mm. Silt falls between sand and clay, measuring from 0.002 mm to 0.05 mm. These size distinctions are crucial for various applications, including construction, agriculture, and environmental science.