Alabaster Case Study

Methods of study
The laboratory study has tow division; the first one is for examining the characteristics of studied alabaster and the weathering process acting on alabaster used in Luxor and Karnak temples. The second division in this work is to examine and evaluate four co-polymer resins selected as stone surface consolidating for the weathered alabaster. Various alabaster samples have been collected from Wadi
Sannur quarry and Wadi Assiuty quarry.
Archaeological samples were taken from the statues and alabaster monuments in
Luxor and Karnak temples. These samples were studied by Polarizing microscope,
Thin sections were prepared from the studied samples, then Petrographical examination and photography was carried out under the polarizing
5. Results and Discussions
5.1. Petrographical characteristics of studied alabaster
The results obtained by polarizing microscopy showed that the alabaster includes three different types.
Holocrystalline alabaster (massive alabaster), where the petrographic examination shows calcite spare crystals with sutured and concavo-convex contacts.
The calcite spars also show blocky sparite fabric, with syntaxial overgrowth. A poikilitic texture is vepresevled. In some parts of the crystalline limestone, the grains are cemented in some parts by iron oxides. Banded or laminated alabaster, where the amorphous carbonate constitutes and the white bands exhibit a well marked colloform structure. Coarse elongated calcite crystals attain about 2-
2.2mm, long and 0.5mm thick, represent the studied banded alabaster. These crystals show rows of fibrous mosaic which is repeated throughout the rock.
Finally, Cavernous alabaster, this type of alabaster is essentially a milky white, crystalline rock with abundant cavities.
These cavities are filled in some parts by red to reddish soils. The unfilled voids are present between the progressive
Archaeological alabaster samples shows less ratio of
Halite NaCl and Gypsum, fig.14 (a, b, c, d, e, f) keV 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00
CPS
0.0
30.0
60.0
90.0
120.0
150.0
180.0
210.0
240.0
270.0
Al
Si S
S
ClCl
K
Ca
Ca
Fe Fe
24
Figure 14 (a, b, c, e, f) XRD pattern of alabaster samples, alabaster consists of calcite (CaCO3) as a major minerals.
5.5. Scanning electron microscope study
The study carried out through
SEM allows us to confirm the result already obtained through other analysis.
It reveled that the main mineral constituent of studied alabaster are calcite grains with cubic and longitude form, fig. 15 (a, b), cemented in some parts by iron oxides. The clay minerals and Gypsum are also exiting among the calcite grains, fig. 16 (a, b, c). Scanning study also indicated sodium chloride in to phases of crystallization, they are cubic form, fig. 17 (a, b) and prisms one like crystals, fig. 18 (a, b). SEM shows the disintegration of Calcite grains and has different weathering noted as grain surface damage and micro-exfoliation due to the effect of soluble salts. Also, it showed the content of gypsum in the samples is due to the transformation of calcite into