Resurrecting a Graeco-Egyptian Purple: Reverse Engineering an Ancient Pigment of Scientific and Cultural Significance

In ancient Graeco­Roman Egypt, funerary portraits painted in the encaustic style often indicated the deceased individual’s socioeconomic status through depicted adornments and clothing. For example, purple clavi ­ such as the clavus in “32.6 The Bearded Man” ­ used their color to distinguish higher social castes from the common population. Traditionally, high­quality purple dye was painstakingly extracted from the Murex sea snail; however, this expensive colorant’s use primarily as a dye rather than a pigment motivated the development of less costly organic dyes for lake pigment production. We explored the processing of several dye precursors accessible to Graeco­Egyptians of antiquity (kermes, lichen, indigo, madder and alkanet roots ­ which can all be color­shifted to purple by a variety of metal and alkali salts) in order to characterize the production of the purple used in “The Bearded Man.” Spectroscopic techniques such as raman, absorption, fluorescence, and XRD offer comparative chemical, physical, and optical analyses of the dyes and pigments that result from the various precursors and the addition of metal and alkali salts. Pigments produced experimentally are compared with a sample from “The Bearded Man” in order to better correlate the processing materials and methods available in ancient Graeco­Roman Egypt

Resurrecting “Poor Man’s Purple”: A Transdisciplinary Study of Color-Shifted Pigments Used in an Encaustic Fayum Mummy Portrait of Ancient Egypt

During the Coptic period in Fayum Egypt, encaustic (i.e. wax) mummy portraits were painted onto wooden panels or linen and attached to the mummy trappings of the deceased. One such portrait, “32.6: The Bearded Man” (c. 170-180 AD), features an unidentified Roman-Egyptian displaying a purple clavi. The trace swath of purple in the portrait provides evidence as to the origins of the painting and the identity of the man. Nanoscale analysis of the pigment suggests a red organic material was color shifted using a metal salt to produce a “poor man’s purple” as opposed to the expensive murex purple traditionally reserved for the elite. It is the goal of this project to reverse engineer the pigment using organic material and metal salts available to the Roman-Egyptians in order to fabricate a purple pigment possessing a similar chemical composition to that within the portrait. Analytical comparisons of the original pigment to our synthesized specimens will allow the identification of the original materials used. Ultimately, our aim is to have an in depth understanding of materials and processes used to create the purple clavi, thereby providing further detail as to the provenience of “The Bearded Man” Fayum portrait