title: Raman spectroscopy of natron: shedding light on ancient Egyptian mummification.
abstract: The mummification ritual in ancient Egypt involved the evisceration of the corpse and its desiccation using natron, a naturally occurring evaporitic mineral deposit from the Wadi Natrun, Egypt. The deposit typically contains sodium carbonate, sodium bicarbonate and impurities of chloride and sulfate as its major elemental components. It is believed that the function of the natron was to rapidly remove the water from the cadaver to prevent microbial attack associated with subsequent biological tissue degradation and putrefaction. Several specimens of natron that were recently collected from the Wadi Natrun contained coloured zones interspersed with the mineral matrix that are superficially reminiscent of extremophilic cyanobacterial colonisation found elsewhere in hot and cold deserts. Raman spectroscopy of these specimens using visible and near-infrared laser excitation has revealed not only the mineral composition of the natron, but also evidence for the presence of cyanobacterial colonies in several coloured zones observed in the mineral matrix. Key Raman biosignatures of carotenoids, scytonemin and chlorophyll have been identified.
authors.affiliation: Chemical and Forensic Sciences, School of Life Sciences, University of Bradford, Bradford, BD7 1DP, UK. h.g.m.edwards@bradford.ac.uk
authors.forename: Howell G M
authors.initials: HG
authors.lastname: Edwards
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Currie
authors.forename: Hassan R H
authors.initials: HR
authors.lastname: Ali
authors.forename: Susana E
authors.initials: SE
authors.lastname: Jorge Villar
authors.forename: A Rosalie
authors.initials: AR
authors.lastname: David
authors.forename: John
authors.initials: J
authors.lastname: Denton
mesh_terms: D001639:Bicarbonates / Q000032:analysis; D002254:Carbonates / Q000032:analysis; D000458:Cyanobacteria / Q000302:isolation & purification; D004534:Egypt; D004615:Embalming / Q000379:methods; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry / Q000382:microbiology; D009106:Mummies; D017693:Sodium Bicarbonate / Q000032:analysis; D013059:Spectrum Analysis, Raman; D013431:Sulfates / Q000032:analysis
chemical_list: D001639:Bicarbonates; D002254:Carbonates; D013431:Sulfates; C012036:sodium sulfate; D017693:Sodium Bicarbonate; C029065:Magadi soda