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Keramický zpravodaj 27 (2) (2011)
After acid leaching, the sample “revealed” other hidden
phases – possibly palygorskite, gypsum, and goethite. The
samples also show a noticeable amorphous phase. It is not
opal substance because this should have its peak located
farther, i.e. between 20-30 °2
Θ
(Co K
α
). The amorphous
phase is unstable in an acid environment, because the dif-
fusion band intensity between 10-20 °2
Θ
(Co K
α
) is app-
roximately the same in both the samples, acidified
and non-acidified (Fig. 6).
The X-ray patterns of geopolymers are characterised by an
amorphous band in the region 20-40 °2
Θ
(Cu K
α
), i.e.
from 23 to 46 °2
Θ
(Co K
α
), as is obvious from Fig. 7. The-
refore, the studied limestone did in no case undergo geo-
polymeric processing.
Davidovits [5] reports that in the samples from the exter-
nal casing in comparison with the samples taken from the
limestone mixed with a binder, natural limestone cannot
be told from the geopolymeric one (see Fig. 8). In case the
geopolymeric limestone was prepared from clay substance
and a source of basic silicate, then it is strange that the
above mentioned amorphous band does not appear, parti-
cularly when so large an amount of binder is present, as
Fig. 7
Diffraction patterns of various geopolymers CuK
α
[5]
shown in the picture. Very probably it is rather a software
suppression of the effect of this amorphous band. It is not
possible that after adding 50 % of amorphous mass to
pure limestone, the equally intensive bands of calcite exist
in this case as well as in pure limestone. Moreover, half
bandwidths in the taken over diagram - Fig. 8 - are diffe-
rent. Therefore it must be an intention to interpret acqui-
red data in a certain way.
IS IT A HAIR IN THE LAUER SAMPLE?
Most of Davidovits’ published works (e.g. [3] [5]) refer to
the sample with so-called hair (Fig. 3). This hair should ser-
ve as irrefutable evidence of the artificial origin of limesto-
ne blocks. Nevertheless, after a closer petrographic investi-
gation, one can state that three possible explanations for
the presence of this so-called hair exist.
Firstly, they can be short and thin cross sections compa-
rable with a cross section of hair, which are grey in colour,
but they are probably shells of fossils. Secondly, it may be
a cross section of a thin terminal fragment of a big scallop
Fig. 8
The first picture shows an X-ray diffraction pattern of samples of Khufu’s Pyramid, and the other picture shows
a record of X-ray diffraction pattern from the analysis of limestone agglomerated with 30 %, 40%, and 50 % of
geopolymer [5].
shell or similar relict, which thanks to dissolving
and during diagenesis can remain and have a thin cross
section similar to that of human hair. The only difference
is that the colour is dead-white in this case. Thirdly, these
hair-like objects can be discontinuities between the layers
of sediments going across and having a serrated profile.
Two of these objects could be seen in the polished secti-
on, and can be identified as microstylolites, as products of
a pressure effect on sedimentary rocks during late diage-
nesis and after it. In this case, these microstylolites are for-
med for a long time, and their presence in the polished