Conservation Showcase: 1855 Half Cent
Posted on 1/17/2011
|click to enlarge||click to enlarge|
Copper coins can show the evidence of improper long-term storage in particular ways and the effects of improper storage can be quick to show. Of the commonly used coin metals, copper will react most rapidly with the outside environment. A residue can turn into corrosion and irreversible environmental damage on a copper coin much faster than it would with, say, a silver coin.
This 1855 Half Cent arrived at NCS covered with a dark residue covering and surrounding much of the key features of its design. The NCS conservators were able to carefully remove the offending residues while retaining the natural look to this classic copper coin. Luckily the residue had not lead to corrosion. This coin, however, might provide a lesson to those trying to conserve coins in an amateur way. An amateur attempt at removing something from the surface of this coin can be seen as scratches between the E and N of CENT in both the before and after images. Though the results of the coin after professional conservation are stupendous, the scratches on the reverse prevented this coin from grading at NGC with standard numeric grading and instead received a details grade.