Effects of pretreatment on a 14 Å swelling mineral from Gartly, Aberdeenshire

Abstract
A 14 Å swelling mineral, interlayered with what is probably an organometallic complex, occurs in the surface horizon of a gleyed soil near Gartly, Aberdeenshire. The interlayer material is thermally stable at 300°C and is easily removed by oxidation with H2O2 and NaOCl. Treatment with HCl and Na2EDTA destroys the ability of the mineral to expand with glycerol, although not if the clay is H2O2 treated beforehand. The Gartly clay mineral is also unusual in that Mg-saturation, using magnesium acetate at pH 7, leads to the rapid formation of brucite-like interlayers. It is concluded that in the investigation of soil clays it is best to avoid all pretreatments.