Conservation Showcase: 1913 Buffalo 5 Cent
Read about a recently conserved coin from the conservation laboratory.
Numismatic circles are filled with the horror stories of coins housed in PVC laden holders for extended periods of time. PVC is a plasticizer used in some coin holders, most notably soft flips, to make them softer and less brittle. Soft flips are intended to be short term storage solutions if used at all. Long term storage can cause the PVC chemical to leach out of the plastic and deposit onto the surface of the coin creating a green residue. With time this green residue can also begin to corrode the surface.
This 1913 D Type 1 Buffalo 5 cent coin was recently submitted to NCS in a sorry state sporting a heavy green coat of PVC residue. With such extensive PVC residues it is difficult to tell if the deposits had lead to any deep corrosion. Very luckily for this coin, the PVC residues were only unsightly and had not done permanent damage to the surface of this first year of issue coin. Careful removal of the PVC residue revealed a bright coin that was able to grade numerically with NGC.