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Experiments in Egyptian Archaeology: Stoneworking Technology in Ancient Egypt

88. Rose granite is a coarse-grained stone, mainly composed of quartz, mica and feldspar, the latter mineral being slightly softer than the quartz (Figure 3.10). The pinkish feldspar, widely distributed within the stone’s matrix, and larger in size than the quartz and mica crystals, made this granite particularly attractive to the ancient Egyptians. The chiselling action on the rose granite is improved if the chisel’s edge is twisted to a new angle of attack, after a preceding blow. In this way, account may be taken of the different quartz crystal positions within the stone. After roughing out the test sign, pointed punches were employed to reduce the chiselled surface to a flatter finish. The characteristic pitted appearance of ancient artifacts was in evidence at the bottom of the sign. These findings were confirmed by experimentally chipping smoothed and polished hard limestone and diorite with flint punches (Figure 3.11).

91. Anciently polished rose granite, because of the abundance of quartz crystals within its matrix, has a feel of glass. Therefore, the polishing of the specimen of rose granite was attempted in the manner in which glass would be polished today, that is, by initially rounding the minute scratches and pits made by the grinding medium, in this case sandstone rubbers, and then polishing with a soft lap and paste. Leather was used as a hand-held lap for the experiments; it may have been used in ancient times. The Egyptians possessed a material which could have been in use for the initial polishing stages. This was a finely ground sand/stone/copper powder, a waste product from the tubular drilling and sawing of stone with sand abrasive. Chapter 4 will investigate this by-product more fully, and its possible uses to the craftworker.

91. Preliminary polishing of the rose granite involved mixing a quantity of the drilling powders, the by-product mentioned above, with liquid mud, and rubbing it onto the granite’s surface with the leather lap. Lastly, to obtain a polish, mud only was utilized, again with the leather lap (Figure 3.16). Mud could have acted as a polishing medium in ancient times, as it is not unlike jeweller’s rouge, which is used for polishing glass today. A fully polished surface would have cost ancient craftworkers much time and energy. The test polishing was not fully completed, and the total time for all the smoothing and the polishing operations was 80 minutes. It was noted that fine clay particles adequately fulfil the requirements of a polishing agent, giving a shallow, rounded shape to sharply defined pits and grooves, which display a frosted appearance on unpolished surfaces. With regard to the ancient nb sign, it is calculated that another 4 hours for polishing should be added to the 8 hours already stated, making a total of 12 hours in all (Figure 3.17).