Bentonite soil is a natural clay material primarily composed of montmorillonite, a type of smectite mineral known for its high water absorption and swelling properties. It forms from the weathering of volcanic ash and has a soft, fine-grained texture.
Key Characteristics:
High Swelling Capacity: When wet, bentonite can expand several times its dry volume.
Plasticity: Easily moldable when moist, but hardens when dried.
Water Retention: Excellent at holding moisture, making it useful as a sealing or lining material.
Low Permeability: Once hydrated, it forms an impermeable barrier to liquids.
Color: Usually gray, cream, or light greenish depending on mineral impurities.