Fig. 6. X-ray diffractograms (Co K radiation) of Red Tank 2Bt3 and LeTrab 2Bt3 clay (<2 µm) (lower diffractograms) and silt (2–50 µm) (upper diffractograms) fractions. Mg = Mg-saturated; Mg-EG = Mg-saturated, ethylene glycol vapor treated; K-EG = K-saturated, ethylene glycol vapor treated; K-550 = K-saturated with heating to 550°C