Wax on, wax off

In my last post, I briefly described the Egyptian storage move project currently underway. And I also promised to feature some of the objects that are in the lab as a part of this project. As conservators, we get excited by lots of things, so I really can’t post images of every single object that comes into the lab, but we will try to post as much as we can here, on Twitter, and on the museum’s Facebook page.

Earlier this week, Alexis brought a drawer of beadwork up to the lab, and this is one of the pieces she found in that drawer:

A piece of beaded fringe that recently came to the Artifact Lab for conservation/re-housing.

A piece of beaded fringe that recently came to the Artifact Lab for conservation/re-housing.

Huh. Not the prettiest object I’ve ever seen. But just wait…

Partially cleaned beadwork

Partially cleaned beadwork

Under that dark material (which is wax) the beadwork is beautiful! We actually see a lot of beadwork in our collection that has been coated with wax, which has now discolored to a dark brown, completely obscuring the colors of the beads. Coating beads with wax was a method used by archaeologists to remove beadwork from mummies during excavation, in order to maintain the correct arrangement of the beads, since the original linen threads were usually mostly deteriorated. In the case of this beadwork, shown above, it was not only waxed, but affixed to a piece of cardboard. Alexis is currently cleaning the wax off the beads and she will eventually re-house this piece for safe transport to the off-site storage location.

Another cool detail – she found this, written on the back of the cardboard:

HapimenbeadsIt says: “E16220B. Bead fringe of Hapi-men, Pl. LXXIX Abydos. From mummy buried with his dog.” This small piece of beadwork belongs to our mummy Hapi-Men, who is currently on exhibit with his dog! Hapi-Men and Hapi-puppy were excavated by Sir Flinders Petrie from Abydos in 1902. You can read more about Hapi-Men and some of our research about him here and here.


Investigation of a mummy bead “coating”

While we continue to work on the conservation of PUM I‘s remains, we also have been taking this opportunity to carry out some analysis on the residues and substances preserved on his wrappings and on the beads that once made up his beaded burial shroud.

Since the last time we wrote about these beads, we have recovered even more in the conservation process; we now have a total of 35 beads – all either tubular or circular in shape. As we wrote about in a previous post, all of the beads are covered with concretions, mostly a brown, waxy material. Here is an image of one of the beads before cleaning, and after partial exploratory cleaning, revealing the beautiful blue color of the bead:

A tubular bead before (left) and after (right) exploratory cleaning to remove the residue on the surface ( 10X magnification)

A tubular bead before (left) and after (right) exploratory cleaning to remove the residue on the surface ( 10X magnification)

This material does not appear to be dirt or accumulated debris from the mummy. But, it can be removed rather easily from the beads, especially with the help of some mineral spirits, which suggested to me that it is some sort of wax.

Based on this information, I was suspecting that either this material was related to a substance applied to the beads to help the beaded shroud stay in place at the time of burial (but we have yet to locating any research supporting this theory – it was more common to sew or tie these beaded shrouds in place) or that it is related to a substance applied to the shroud at the time of discovery, to assist with the removal of the shroud.

In conservation, when it comes to investigating unknown, likely organic substances, there are several analytical techniques that can be helpful. One of these techniques is Fourier-transform infrared (FTIR) spectroscopy. FTIR works by exposing a sample to infrared radiation, which causes the sample to selectively absorb radiation, depending on the molecules present. The individual peaks in the resulting absorption spectrum can be analyzed or the spectrum can be compared to reference spectra to help characterize or identify a material.

We provided a small sample of our “bead coating” to Gretchen Hall, a consulting scholar in the Biomolecular Archaeology lab here at the museum. She ran the sample for us and provided the resulting spectrum and interpretation. Here is the spectrum produced by our sample:

E2813A_FTIR_beadThis spectrum shows that the sample is mostly organic as evidenced by the dominant peaks in the 2900 cm-1 region which are characteristic of C-H bond stretches.  In addition, there were many peaks in the “fingerprint” 1800-1000 cm-1 region where various organic molecules absorb. The absorption around 1730 cm-1 (due to C-O double bond stretches) suggests organic acids are present, possibly from resins or beeswax. Both of these families of compounds would also have bands around 1470 (a O-H bending absorption) which are seen in our sample. Importantly, the sample also shows a strong band around 720-730 cm-1 (due to the C-H in long hydrocarbon chains) which is only present in beeswax.

For comparison, here is our bead coating sample spectrum displayed just below the spectrum for a standard beeswax:

E2813A_FTIRBased on this analysis, our “bead coating” sample likely contains some beeswax, which is consistent with our observations of the solubility and consistency of the material as well. It is known that beeswax was used in ancient Egypt – as an adhesive, a sealant, a binding medium, and in the mummification process. Bees were considered by the Egyptians to be precious insects with magical and economic prestige, and these values would have extended to their wax (Ikram and Dodson 1998).

For a more definite identification of our sample, the next step would be to analyze the material using gas chromatography–mass spectrometry (GC-MS).

Special thanks to the Biomolecular Archaeology Lab and Dr. Gretchen Hall for running this sample and providing the analysis.