Bakersfield CollegeSoils B1Burroughs | 1Chemistry of ClaysWe will begin this chapter by looking at the chemistry of clays–what and how they are madeup and the characteristics conferred upon them because of their chemistry.Clays arecolloidsmeaning that the particles that make up clays are so small that their surfaceforces overcome gravity. These types of particles remain suspended in water, form pastes orglues when wet, and stick together when they are dry. Clay itself is a“crystalline colloid”meaning that the atoms that make up the clay are arranged in a specific order or repeatingunits. These crystals are formed from the precipitation of dissolved minerals our of watersolutions.Structure of ClaysIn general, clays are composed of alternating layers of oxygen, silicon, aluminum, hydroxyl, andiron that are held together by ionic bonds. Ionicbonds are relatively weak positive-negativeattractive forces. The layers of bonds that makeup these clays are hexagonal (Stop-sign) shaped.The type of clay and its properties are determineby the elements it consists of, the order of thoseelements, and the number of layers making upthe clay.The most basic clay crystals,Micelle (mee-cell) are composed of one clay crystal made up of manysandwiched layers of 3 or 4 planes of oxygen, silicon, and aluminum. All clayshave a plus or minus negative charge because of the abundance of oxygen andhydroxyls.
