November News from the Conservation Lab — stone survey discoveries!

By Caroline Roberts, Conservator

 The stone condition survey is well underway, and I am just floored by the richness and variety of the Kelsey’s stone collection. We’ve got limestone that is packed full of shell fossils (fig. 1), alabaster that has weathered in a way that it looks like a sea sponge … and, best of all, so much of the material comes from sites that were excavated by the University of Michigan. If I had to choose the most exciting artifacts I’ve encountered so far, it would be those from Karanis, Seleucia, and Terenouthis. I’m a self-professed ancient color geek, and an incredible number of these objects still have pigment preserved.

limestone with fossils
Figure 1. Shell fossils visible along the side of KM 29001, a limestone funerary stela from Terenouthis, Egypt, late 2nd–early 4th century CE.

Take the Karanis stone. I’ve seen hefty jar bases that have traces of pigment and ground still in place, and a libation altar decorated with a vivid orange-red pigment (red lead?) barely visible under a thick layer of burial dirt. At least half of the Seleucia sculptures I’ve examined have traces of pink pigment, including one with a highly detailed painted necklace. I’ve spent years studying the Terenouthis funerary stelae, and even these continue to surprise me. I spotted blue-green pigment on a well-preserved stela that I am eager to investigate further (fig. 2).

carved funerary stela
Figure 2. Limestone funerary stela from Terenouthis, Egypt, late 2nd–early 4th century CE. Traces of green pigment can be seen in the figure’s left hand and on the recliner cushion. KM 21159.

In addition to revealing the extent of surface decoration on the Kelsey’s collection of stone, the survey is also helping me determine which artifacts are in need of treatment or rehousing. It’s amazing to me how much there is to learn from objects in the collection even now, in some cases nearly ninety years after their discovery.

Ugly Object of the Month — August 2019

By Caroline Roberts, Conservator

My survey of the Kelsey’s stone collection has proven to be a rich source of material for our Ugly Object blog roll. Stone can be durable, which is why we build with it and why so many ancient structures remain. But like many things that seem tough, stone has a less visible softer side. Sedimentary stones, especially, can break down over time into fuzzy, diminished forms of their former selves, which is what has happened to the stela fragment featured here.

fragment of rock with etched shape of a woman.
Limestone funerary stela incised with a symbol of Tanit. 12.3 x 7.4 cm. Punic period. Carthage, Tunisia. KM 84.

Although the artifact’s surface is scuffed and weathered, we can still make out a triangular, incised female form. This unassuming figure is a symbol the Punic goddess Tanit, a deity worshipped in Carthage and who appears in many forms of ancient North African material culture. The Tanit symbol is simple but powerful, and redeems this otherwise lackluster fragment of limestone, which can be seen on display in the Roman Provinces gallery of the Upjohn exhibit wing.

News from the Conservation Lab — Stone Survey!

By Caroline Roberts, Conservator

This summer I’m embarking on a condition survey of the Kelsey’s stone collection, a big project both in scope and in terms of artifact size. As I mentioned in our latest Ugly Object post (ancient earplugs!) the Kelsey’s stone collection is wide-ranging, including everything from tiny steatite scarabs to massive column drums the size of tree trunks. My survey will focus on the larger-scale artifacts and will include vessels, sculpture, and architectural elements made of stone. My goals are to identify which of these artifacts are most in need of conservation intervention, and in the process learn what I can about past stone conservation treatments.

woman with clipboard
Carrie examines stone artifacts in the Kelsey’s collections storage.

The project is a continuation of previous condition surveys conducted by Suzanne Davis, Claudia Chemello, and LeeAnn Barnes Gordon. Their work serves as a valuable baseline for how the Kelsey’s stone artifacts might have changed over the past ten years. Gordon’s research also revealed information about how newly excavated stone was treated at the Roman-Egyptian site of Terenouthis. In the early twentieth century, archaeological chemist Alfred Lucas introduced polymeric materials to archaeologists’ conservation toolkit. Among these was Duco cement, a cellulose nitrate adhesive that was applied to many of the stelae discovered at Terenouthis in order to prevent rapid surface deterioration following excavation. The Duco coating has, however, started to deteriorate, compromising the very surfaces it was meant to protect. Information about historic conservation treatments, along with new condition rankings, will help me develop preservation and treatment plans for the most at-risk stone artifacts at the Kelsey.

stone stela in situ.
Limestone stela during excavation at Terenouthis, Egypt. Kelsey Museum Photo Caption Database.