X-Ray diffractometry is used to determine semiquantitatively the content of minerals belonging to the mica-, chlorite-, smectite- and kaolinite group in the fractions < 20 µm or < 2 µm. After ion exchange with potassium and magnesium, textured samples are prepared on ceramic plates. Identification of clay minerals is based on expansion characteristics following solvation with glycerine and dimethylsulfoxide. Additionally, the content of non-sheet silicates (quartz, feldspar, carbonates) from non-textured samples is determined. An effective smectite content can be calculated based on the grain size content < 2 µm.
Equipment: Philips PW 1830 (Cu-tube) © TU Graz/IAG
Reference Standard: ÖNORM B4810