lermineraler

Lermineraler, or clay minerals, are a group of hydrous aluminium silicates that form the fine-grained fraction of soils and sediments. They are phyllosilicates with layered, sheet-like structures and very small particle sizes, typically less than 2 micrometres, which gives them a large surface area, high plasticity when wet, and notable adsorptive properties. They originate mainly through the chemical weathering of silicate minerals such as feldspars and micas, or by diagenetic and hydrothermal alteration of existing clay or aluminosilicate minerals.

The structure and classification of lermineraler are mainly based on their layer configurations. One common division is into 1:1 clays, such as kaolinite, which consists of one tetrahedral sheet linked to one octahedral sheet, and 2:1 clays, such as illite and montmorillonite (smectite), which have two tetrahedral sheets around an octahedral sheet. Isomorphous substitution within these layers creates negative charge, which gives the clays a role in cation exchange. Some clays exhibit swelling behavior (notably montmorillonite), while illite and kaolinite are less prone to swelling. Mixed-layer and chlorite group clays add further diversity to properties and behavior.

Common lermineraler include kaolinite, illite, montmorillonite (smectite), chlorite, and their mixed-layer assemblages. Their properties—surface area, charge, swelling, and plasticity—control soil fertility, water retention, and stability of soil structure. In geology, clay mineral assemblages serve as indicators of weathering intensity and past environmental conditions. Industrially, they are used in ceramics, drilling fluids, fillers, and as adsorbents in environmental applications.