Monorthic -Kaolinite, halloysite and or fully hydroxy interlayered vermiculite (HIV) dominate the clay fraction. If smectite is present it should be at low concentrations such that it is not identifiable by appropriate mineralogical analyses (usually less than 10%). Usually the clay fraction CEC at pH 7 is < 30 meq/100g. Coarse fractions are typically siliceous (>90% quartz+resistant minerals).