ISOLATION AND CHARACTERIZATION OF AN IRON-RICH CHLORITE-LIKE MINERAL FROM SOIL CLAYS

Reports on the isolation and characterization of a naturally occurring Fe-rich, 1.4-n, nonexpanding chlorite-like interphase from soil clays. The mineral was isolated from the coarse clay fraction of a Boralf (Gray Luvisol) from Saskatchewan, by using a high-gradient magnetic separation (HGMS) at 0.20-T level of magnetic flux density (MFD). While most chlorites contain Fe2+, analyses showed that all the Fe in this mineral was in the Fe3+ form. It is suggested that the mineral isolated is an Fe-hydroxy interlayered vermiculite rather than a true chlorite. Regarding the genesis of the isolated mineral, two possibilities exist: the Fe lost from the octahedral layer of an original mica would have been responsible for the formation of an Fe-hydroxy interlayer, thus producing a chlorite-like mineral, or the interphase may have resulted from weathering of an original chlorite since chlorites were detected in the soil parent material. -from Authors