ABSTRACT
Mineral grains are solid particles which reflect the developmental history of the soil. Minerals are solid, naturally occurring chemical compounds which have been formed mostly through inorganic processes. The study of mineralogy includes the identification of minerals, their physical and chemical properties, origins, and classification. Subdivisions include chemical composition, physical properties, and crystallography. Minerals in soil can also be subdivided into two general mineral groups reflecting their process of formation: primary minerals and secondary minerals. Primary minerals are typically inherited from parent materials. Secondary minerals typically result from the weathering and transformation of primary silicates. Primary silicates in soils are derived from the physical disintegration of parent rock material. Oxides and hydroxides represent the end product, and form either from the weathering of primary silicates or from the hydrolysis and desilication of certain clay minerals (smectite and kaolinite).
