Calcareous clay mixed with ferruginous clay with a slighly optically active matrix. Distinctive is a banded pattern of the two clays visible macroscopically. 11% inclusions, low porosity. The calcareous clay can be identified as base clay and contains primarily micrite and quartz. The ferruginous component includes amphiboles, plagioclase , hornblende and sporadic micas. This is an intentional clay mixture of "Egyptian Marl Clay" and minor amounts of Nile sediment. An origin from the nothern part of Upper Egypt might be supposed, but not verified.

IFAO 5525