Here is the location of the area where Dr. Davidovits apparently obtained the limestone sample at Giza for his disintegrating rock experiment cut out or whatever from the NOVA program "This Old Pyramid" in 1991. Claims about certain rocks at Giza disintegrating into loose sediments are discussed on the Geopolymer Institute's website and in a number of books and research papers over the past 18 years of so. The sample of limestone from this area has been claimed to disintegrate into sediments in 5-10 hours by soaking in a bag of water (Davidovits c2006) or within 24 hours (Morris 1993).

The location of the site appears to be on the north side of the eroded-rockcut Mastaba of Tomb I (5th-6th dynasty), found in the outer, south-central portion of the Central mastaba field and on the east side of the quarry of Khafre used in the construction of his pyramid. As seen in the image below this area contains some of the same strata as that exposed on the surfaces of Mastaba of Khentkawes (a large, and well-known, carved limestone rockcut).

Fig. 1. Location of NOVA sample site.

(Photograph by Jon Bodsworth (The Egypt Archive))

Fig. 2. NOVA sample location.

(Photograph by Jon Bodsworth (The Egypt Archive))

Fig. 3. Sample location closeup (center of Fig. 2).

(Photograph by Jon Bodsworth (The Egypt Archive))

This tomb (which is not a quarry anymore) is extremely eroded as a direct result of salt weathering due to exposure to the atmosphere and agents of erosion such as wind, rain, and gravity (somewhat similar to the Sphinx). The area at the bottom of the tomb that has been buried and now is exposed due to recent excavations shows much less erosion. It appears to be a harder limestone bed since it continues to be exposed on the east side of Mastaba of Khentkawes and exhibits similar erosion morphology on carved surfaces.

The limestone of the Giza Plateau often contains colour banding in association with solution widened joints (Gauri & Bandyopadhyay 1999). The limestone of the NOVA tomb above is permeated with colour banding and jointing. Here colour banding is seen as curved lines converging on and radiating away from what is now eroded solution-widened joints. These colour bands represent the rhythmic precipitation of minerals in the limestone from a water table that was residing during the eperiogenesis of the region (Gauri & Bandyopadhyay 1999). The flow of water through some of these joints during this period has also formed the solution-widened joints. That is that these rocks were exposed to groundwater for long periods of geologic time and they did not disintegrate.

I have no idea what Dr. Davidovits was testing in his claimed NOVA experiment but one should think it was, at the very most, just some weathered detritus (loose on the surface or part of eroded jointing), and not an unweathered sample deliberately extracted from this tomb's surface(that would be even more of a real shame if it was, although some credit must be given to Dr. Davidovits because when he challenges his readers to conduct their own disintegration experiments at this site he also adds afterwards that one needs permission from the authorities to take specimens (Davidovits 2008)). Fine-grained, salt weathered detritus (often cemented together with salt) probably would break apart in water overnight), however this would be a thin veneer on the surface of the outcrop. The unweathered limestone rocks beneath do not disintegrate in water overnight or whatever, to insinuate such is absurd and shows, at the very least, a complete lack of an understanding of basic geology. So we can put this in the same place as the claims of zeolite geopolymer binder cementing together the pyramid block (which seems to be quite elusive to anyone looking for it even in specimens claimed to contain such.... including some of the geopolymer crowd (Barsoum et. al. (2006)), it is after all based in part on the rock's ability to disintegrate in water overnight by the vast concentrations of kaolinite which is the main source of Al for the non-existent zeolites.

Barsoum, M.W., Ganguly, A. & Hug, G.(2006) Microstructural Evidence of Reconstituted Limestone Blocks in the Great Pyramids of Egypt. J. Am. Ceram. Soc., 89, 3788–3796.

Davidovits, J. (c2006) La Nouvelle histoire des pyramides. Jean-Cyrille Godefroy, Paris

Davidovits, J. (2008) They built the pyramids. Geopolymer Institute, 288 p.

Gauri, K.L. & Bandyopadhyay, J.K. (1999) Carbonate stone: chemical behavior, durability, and conservation. Wiley, New York, 284 p.

Morris, M. (1993) How Not to Analyze a Pyramid Stone - The Invalid Conclusions of James A. Harrell and Bret E. Penrod. Journal of Geological Education, 41, 364-369.

Archae Solenhofen (solenhofen@hotmail.com)