Coin BK-36
from the Athenian Agora excavations
Coin before treatment
Coin after treatment
Condition before treatment
The object is a copper alloy coin with burial soil deposits on both sides, obscuring any surface details. The object has a crack running halfway its diameter, from the edge up to its center. After investigative cleaning, it was observed that the coin retains some surface details and lettering in the form of raised relief.
The coin is overall stable apart from signs of bronze disease on one side, in the form of light blue/green powder and some voluminous corrosion products in the form of light blue-green bubbles and some dark brown waxy products.
Treatment
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Burial deposits were softened with ethanol and removed mechanically with a scalpel under magnification. Corrosion products were reduced with a scalpel under magnification.
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The coin was degreased with ethanol before packaging.
Coin BK-35
from the Athenian Agora excavations
Coin before treatment
Condition before treatment
The object is a copper alloy coin with burial soil deposits on both sides, obscuring any
remaining surface details. There is loss of original material on its side, missing about ¼ of the object.
After investigative cleaning, it was observed that the surface was extensively corroded and fragile and no identifiable details remained. The corrosion layers are a light green surface patination and a waxy light brown and a harder and darker brown product. There are pits present throughout the surface and it easily delaminates.
Treatment
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Burial deposits were softened with ethanol and removed mechanically with a scalpel under magnification. Corrosion products were reduced with a scalpel under magnification.
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The coin was degreased with ethanol before packaging.