39th Annual Meeting-Objects Session, June 1st, “An Archaeological Journey: The Excavation, Deterioration, and Treatment of a Painted Glass Miniature from Nimrud” by Ariel O’Connor

In the first session of talks of the Objects Specialty Group, which  focused on archeological materials, Ariel O’Connor gave a presentation on an incredible treatment she did on a painted glass miniature from the site of Nimrud. I found the  treatment incredible for several reasons.  First she worked on one of the earliest examples of painted glass,  and archaeological glass is one of my favorite materials to work on.  The miniature was from Nimrud, and having worked at the Oriental Institute Museum I had become familiar with the amazing finds from the site.  But the main reason it was so incredible was because of the amount of work it must have taken to reconstruct the miniature that was in such a fragile and fragmentary state.  Some of the pieces Ariel reattached were only the size of the tip of a fine brush!

Ariel worked on the miniatures in 2009 during her internship at the Metropolitan Museum of Art.  The plaques had been excavated in the 40’s from the site of Nimrud (located in Iraq near Mosul) by the archaeologist Max Mallowan, husband of the author Agatha Christie (who also participated on the excavation cleaning some of the ivories found).  Nimrud was once the capital of the Assyrian Empire and had palaces, temples and an acropolis.  Most of the finds from the site date to the 9-7th c. BCE.

The Met’s miniature was found in a room at Fort Shalmaneser along with several other painted glass miniatures (total of 9).  The room also contained other luxury goods such as ivory plaques and inlays.  The miniatures, which some have suggested could be inlays for ivory, are thought to date to the 9-8 c. BCE.  The plaques are the earliest examples of painted glass in the Near East (and possibly the oldest examples known anywhere).  After the excavations were completed, the finds were split between the Met, the British Museum, the Iraq Museum and the Corning Museum of Glass.  All the plaques were examined by Robert Brill who conducted a technical study of them.

The miniature from the Met is comprised of two fragments which make up the top half of a winged sphinx with a lotus flower. The miniature is rectangular in shape, resembling a plaque, and concave. The piece seemed to be in somewhat good condition when first brought to the museum but by 2002, it seemed to have deteriorated severely and was in about 85 pieces.  Ariel set about to conduct a technical study of the pigments used to paint the decoration and undertook an extensive treatment of the miniature in order to stabilize and reconstruct it.

FTIR and Raman analysis was done in order to identify the materials used to paint the design.  Iron oxide red and Egyptian blue were found.  The black material was analyzed using FTIR but could not be identified.  This is because the plaque had been consolidated in the field with PVA which was affecting the analysis.  In Brill’s earlier study of the plaques, he hypothesized that the black material was bitumen, which was commonly used in the Near East.  Solubility tests of the black showed it was not affected by solvents.

Treatment of the piece proved challenging not only because of the fragile and fragmentary nature of the miniature, but because of the presence of the PVA consolidant.  Ariel had to find a treatment to consolidate lifting areas of the miniature and to reconstruct the fragments, but which would not affect the previously applied PVA.  She decided to use methylcellulose to join the fragments, which would then be supported by Japanese tissue as a single fiber laid across the join.  She used an enlarged image of the miniature that was taken in 1959 to aid in reconstruction. For areas which had separated between the top and bottom surfaces of the miniature, she created an internal support made up of several layers of Japanese tissue.

The final step of the treatment was to fill areas of loss to provide further support to the fragile plaque.  Using Mylar, she cut out small templates of missing areas and then cut Japanese tissue to shape using the template.  The tissue was then placed in the areas of loss.  The edges were also filled, either using one long piece of tissue or smaller pieces only over missing areas, depending on how severe the deterioration was.  The tissue fills were not toned, but left as is.  After treatment she compared the conserved piece to the 1959 photo and noted there were no losses, just cracks.  That was an impressive feat given the number of fragments and how small they were!

Due to deterioration during burial, there had been loss to the original pigments and to the surface.  To better understand what the miniature would have looked like, Ariel made a reconstruction, pictured below. I found the talk really interesting and the treatment results very impressive.  After all that work to reconstruct the numerous small fragments, the plaque is now stable and the decoration is intelligible once again.