ROYAL ONTARIO MUSEUM'S ROMKOMMA PROJECT

 

One of the ancient Greek coins from the ROM's collection analyzed at OCCAM (top left). A zoomed-in view of a section of the coin showing a corrosive product (top right). SEM-EDS maps of the section of the coin. The analysis suggests the nature of the corrosion product is silver chloride (bottom left and right).

Researchers at the Open Centre for the Characterization of Advanced Materials (OCCAM) are working with the conservation team at the Royal Ontario Museum (ROM) to help preserve links to the past, ensuring important historical artifacts can be studied and shared with generations to come.

Maria Stanko (MSE 2T2 + PEY, MSE PhD candidate) and her collaborators are studying the surfaces of two corroded Greek coins from the Hellenistic period, dating back to 300-115 BCE, using OCCAM's instrumentation. By understanding what is happening to these priceless relics, the team will be equipped to advise researchers and conservators on how to best conserve and store these artifacts safely.

The coins are subjects of study for the ROMkomma project, a collaboration funded by the Social Sciences and Humanities Research Council and led by Professors Kate Cooper (UTSC Historical and Cultural Studies), a research associate at the ROM, and Ben Akrigg (Classics). The project aims to catalogue and publish data on the ROM's extensive collection of ancient Greek coins, which contains more than 2,000 coins. This investigation, which will make the ROM's Greek coin collection accessible online, could reveal important insights on early minting practices and how early economies were developed.

Environmental degradation is normal with coins that are thousands of years old, says Stanko. On a few of these coins, we're likely seeing corrosion caused by elements like chlorine and bromine.

These corrosive products are harder than the coin itself. We risk damaging the artifacts and removing the fine surface detailing if we try mechanical cleaning methods.

She and her colleagues, including Dian (Jack) Yu (MSE 2T1, MSE PhD candidate) and Dr. Michel Haché (MSE PhD 2T3), an MSE postdoctoral fellow, along with Stanko's PhD co-supervisor Professor Jane Howe (MSE, ChemE), developed a strategy to examine the coins with a scanning electron microscope paired with energy-dispersive X-ray spectroscopy (SEM-EDS).

Once we know more about the chemical composition on the surfaces of these coins, we can advise ROM conservators on non-destructive treatment strategies and storage solutions, Stanko says.

To read the complete article, see:
U of T Engineering's OCCAM partners with Royal Ontario Museum to preserve ancient Greek coins (https://news.engineering.utoronto.ca/u-of-t-engineerings-occam-partners-with-royal-ontario-museum-to-preserve-ancient-greek-coins/)

For more information, see:
ROMKOMMA (https://romkomma.artsci.utoronto.ca/)
The ROM's ancient Greek coin collection sure to profit from the ROMkomma project (https://www.artsci.utoronto.ca/news/roms-ancient-greek-coin-collection-sure-profit-romkomma-project)

	NBS (coinbooks.org) Web