We love ugly objects too!

Last week, I posted some photos of a beautiful stola coffin lid that I’m working on at the moment, and I mentioned that this lid might be my new favorite object. I now somehow feel a need to post images of some objects that aren’t necessarily as pretty, but I want to assure you that we’ll give them just as much lovin’ here in the conservation lab.

A Nubian jar, ca. 100 BCE-300 CE and ivory horn protectors from Kerma (Sudan), ca. 1650-1550 BC

A Nubian jar, ca. 100 BCE-300 CE and ivory horn protectors, Kerma (Sudan), ca. 1650-1550 BCE

A cat mummy head, unwrapped, Thebes, ca. 664-332 BCE

Cat mummy head, unwrapped, Thebes,                 ca. 664-332 BCE

Sections of a beaded mummy shroud covered in wax

Sections of a beaded mummy shroud covered in wax, Egypt, exact site and date unknown

I also feel the need to mention that I don’t just love pretty objects. My most favorite “object” that I’ve worked on here in this lab in not an object at all, but a mummy – our Predynastic mummy Bruce, and I don’t think anyone would call him pretty. But please don’t take that the wrong way (I don’t think he would be offended either). My interest in him goes way beyond his looks.

I promise to post photos of what the objects in the images above look like before they leave the conservation lab. Conservator Alexis North will be working on these pieces (along with some help from our interns) in the upcoming weeks.

This post was inspired in part by a great blogpost on the Kelsey Museum of Archaeology’s blog, “Ugly Object of the Month“. Enjoy!


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.