Wednesday, February 1, 2017

Deanna O'Donnell on "What is Glass Bead Disease?: A study of the Fort Union Trade Bead Collection"

Thursday, February 9, 2017 at 6pm, John B. Davis Lecture Hall in the Ruth Stricker Dayton Campus Center, Macalester College

Glass Bead Disease is an irreversible, degradation process that leaves the surface of the glass with microfractures, pitting, and a white ‘crust’. The number of studies that have explored the cause of glass disease in beads over the past five decades is small.  Conservators have observed acceleration in the degradation for beads attached to corrosive natural materials. Blue beads are especially susceptible, suggesting the colorant plays a role in the process.  Fort Union Trading Post has a unique collection of Native American glass trade beads, both in its size and history.  The beads have not been used, so their condition can be attributed to natural weathering.  In July 2015, 81 beads from the Fort Union collection were analyzed by optical microscopy and portable X-ray Fluorescence Spectroscopy.  The majority of the beads were blue hollow cane beads that varied in condition.  This pilot study aimed to identify chemical trends within the glass composition that were correlated to condition to potentially identify a chemical fingerprint conservators and curators could use to predict vulnerable glass artifacts. In this talk, Dr. O’Donnell will present their preliminary findings.

About the speaker: 
Deanna O’Donnell is an Assistant Professor of Chemistry at Hamline, where she teaches Analytical Chemistry and Instrumental Methods.  She began her scientific career at McMaster University in Canada receiving her BS degree in Chemistry. She earned her PhD from the University of Notre Dame in Physical Chemistry where she studied aqueous radicals using Time-Resolved Resonance Raman Spectroscopy. Dr. O’Donnell continued her training in a joint postdoctoral appointment at City College of New York and the Metropolitan Museum of Art. Her post-doctoral work focused on developing Surface-Enhanced Raman Spectroscopy as a nondestructive method to analyze molecular dyes found in cultural heritage objects and controlled substances in forensic evidence. During her post-doc, she was also an adjunct instructor at John Jay College of Criminal Justice teaching General Chemistry. At Hamline, Dr. O’Donnell has continued to develop analytical methods for the analysis of small molecules relevant to the fields of forensic sciences and cultural heritage.

*Location and parking information can be found here (#29 on the printable map at the bottom of the link)

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