A stone stela is engraved on a rock at the island Sehel, near Elephantine, Egypt, north of Aswan. This monument is claimed to illustrate the invention of building with stone. Yet, the most controversial aspect of this text resides in the fact that to build temples, pyramids and other sacred buildings, Khnum's instructions and Imhotep's revelations do not mention any contructional stone , such as limestone or sandstone or granite blocks. These materials are not found in the list. To build monuments, Zoser was given a list of minerals and ores whose hieroglyphic names have not been translated so far.
All translations relate to the hieroglyphic word ' aa ' and the determinative for pyramid.
According to Sethe and Barguet, this word 'aa' is an archaism from the Old Kingdom. This verb occurs three times. The adjective, ARI, designates an artificial material, for example synthetic lapis-lazuli.