Nader Makarious

Chemistry Teacher

@ Brandywine High school

1400 Foulk Rd, Wilmington,DE 19803

Tel:(302)-479-1600 ex# 1060

e-mail: nader.makarious@bsd.k12.de.us

 

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Ancient Egyptian cosmetics and chemistry


An analysis of Egyptian cosmetic powders dating back to as early as 2000 BC revealed an unexpected level of sophistication in the 'wet' chemistry practised by the ancient Egyptians.

It was already well-known that they were using fire-based technology to produce their blue pigments prior to 2500 BC. Yet this is the first time that the analysis of the black, green and white cosmetic powders shed light on the level of their practices in chemistry.

Researchers identified a number of organic and mineral ingredients in the powders. Two of the mineral ingredients were naturally occurring ores which were crushed, ore of galena (PbS) and cerussite (PbCO3). However, the surprise came from laurionite (PbOHCl) and phosgenite (Pb2Cl2CO3), which were both compounds which occurred rarely in nature. They are found when lead artefacts are weathered by sea water. Or in the case of phosgenite, the compound could also be found when lead-containing minerals were exposed to carbonated and chlorinated waters.

The researchers ruled out the possibility that these compounds were extracted from scarce natural sources since they were too abundant in the preserved cosmetic samples. Also they ruled out the alteration of the other natural lead compounds in the make-up as a source. And in doing so, they arrived at the conclusion that the Egyptians were capable of artificially synthesising the compounds.

They reconstructed the process which the Egyptians probably used by following recipes documented by classical authors. According to the ancient recipe crushed purified silver foam (PbO) was mixed with rock salt and sometimes with natron (Na2Co3). This mixture was filtered and the procedure was repeated daily for several weeks.

The authors recreated the process using PbO and salt powders in carbonate free water. The resulting precipitate was successfully identified as laurionite. The same process in the presence of carbonate would produce phosgenite.

Given that the procedures required repetitive operations, the manufacturing of these compound revealed a previously unknown level of sophistication of ancient Egyptian chemistry.

Original article: Nature, 11 February 1999; Making make-up in Ancient Egypt, P. Walter et al., p. 483-484 D. Hirokawa, Elsevier Science Channelhttp://www.abc.net.au/science/news/stories/s18834.htm


 

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