MCI Project Summaries 2008 - Smithsonian Institution

National Museum of African Art
MCI 6248 African Beaded Dress: Characterizing Deterioration Issues and
Investigation of Cleaning Treatments
MCI Staff: R. Jeff Speakman, Nicole C. Little, Judy Watson, Jennifer Giaccai, Maria Fusco
An intensive study on South African Ndebele beaded objects in the collection of the
National Museum of African Art has been completed. The Ndebele objects are all beaded on a
textile, frequently leather, but occasionally canvas, and even one case on a synthetic knit textile.
Among the beaded aprons, a number of glass beads that have degraded in contact with a fatty
substance have been found. The aprons all have a distinctive appearance—as if an ointment was
rubbed onto the beaded aprons. The ointment on both the leather aprons themselves as well as
the greasy substance found on the beads was analyzed extensively with FTIR, XRD, SEM-EDS
and XRF at the Museum Conservation Institute. As the glass beads deteriorate they form fatty
acid soaps with the ointment that was rubbed onto the apron. It is still unclear whether the fatty
ointment causes the bead deterioration, or if the ions freed during deterioration of the glass later
interact with the fatty ointment to make fatty acid soaps.
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