Ti-bearing minerals in sedimentary kaolin deposits of Egypt

The occurrence of anatase as uniform very fine-grained crystals as pockets within the kaolin mass, together with the presence of ilmenite and/or leucoxene in the sand fractions of the studied kaolin samples suggests an authigenic origin for the anatase as a result of post-depositional alteration of ilmenite precursor to leucoxene. The positive correlations between TiO2 and trace element contents probably support this assumption. The higher trace element contents in the anatase from different deposits compared to the associated leucoxene and ilmenite are considered to result from relative enrichment of the immobile trace elements during the alteration of ilmenite and leucoxene to anatase.