Maciej Pawlikowski
A geological, mineralogical and chemical investigation of stone blocks of Abu Rowash pyramid of Djedefre (4th dynasty) was performed during a geological expedition organized by AGH – Cracow Univeristy of Science and Technology, Poland, in 2006. Moreover, the substance cementing stone blocks as well as the limestone underlaying the pyramid was tested. The examination was performed using polarizing light microscopy, X-ray diffractometry and SEM.
The results show that the pyramid blocks represent various types of limestones and dolomites that contain an admixture of quartz, calcitic skeletons of organisms, opaque and other minerals (sulphides). The porous structure of stone blocks suggests that the deposits of rocks at the quarry were wet, soft and very easy to cut. After a process of preparation and drying they started to set. This phenomenon allowed for a relatively easy production of numerous blocks at a short time.
Furthermore, the investigation confirmed that the natural rock present just under the pyramid represents pure limestones of other type than blocks used for pyramid construction. It means that blocks used for pyramid construction are not of local origin.
On the other hand, an examination performed using microscopic as well as X-ray diffraction method confirmed that the substance cementing blocks of the pyramid in Abu Rowash represents gypsum with different admixtures of small grains of limestone. The material mentioned was used for the fixation of non-symmetric blocks and for filling in the space between blocks.
This data confirms both the knowledge of artificial production technology of technical gypsum Egyptians had at the time of 4th dynasty, as well as the way they used this material for constructing architectonic objects.
On the other hand, field observations clearly show that the pyramid at Abu Rowash was constructed on a small natural but specially prepared hill. The slopes of this hill were built in the form of steps. Next, the steps were used for locating stone blocks. The observations mentioned confirm that the pyramid is constructed as a block cover coating the center (core), which represents a specially prepared, natural hill.
The center of this hill was explored and prepared in the form of a shaft where natural walls were also coated with limestone blocks.
The investigation that was carried out suggests that other Egyptian pyramids are constructed in a similar way and may contain a natural core in the form of a small specially prepared hill. The slopes of the hill were probably similar to the ones at Abu Rowash and cut in the form of steps used later for the deposition of blocks. It is possible that even those small hills (cores) were artificially prepared by the exploration of some parts of their natural layers. This was the easiest way to construct all pyramids than building them of blocks.
The data collected suggests that other pyramids were at all levels constructed only of stone blocks. However, the concept regarding other pyramids has to be confirmed by a detailed examination of other pyramids except for Abu Rowash, where the investigation was successfully completed.
Maciej Pawlikowski, Ph.D.– university professor, mineralogist, geologist working in Egypt since 1979 (Hieraconpolis, Deir El Bahari, Armant, Fayum, Delta and other), Institute of Mineralogy, Petrography and Geochemistry, AGH-Cracow University of Science and Technology, Poland.
Light fine crystallized gypsum used as material cementing blocks of Abu Rowash Pyramid
Light, laminated natural limestones cut in form of steps at the core of Abu Rowash pyramid
Coridor leading to the tomb. One can see walls cut in natural limestone and coated with blocks of not local limestones
Bottom of the tomb. Blocks of limestones used for construction of architecture at the tomb. One can see rests of plasters at the surface of cut wall used as material fixing blocks with natural wall
