NCS Conservation: Residue Carefully Removed

Numismatic Conservation Services™ (NCS®) uses a variety of proprietary techniques to remove harmful contaminants, stabilize and protect a coin's surfaces and, in many cases, improve a coin's eye appeal. After coins are conserved by NCS, they are seamlessly transferred to Numismatic Guaranty Company™ (NGC®), an independent affiliate of NCS, for grading and encapsulation.

Below are a few highlights of coins that were recently conserved by NCS and graded by NGC.

Some coins can develop some terrifying residues through some dreadful long-term storage conditions. This Great Britain 1931 Crown was recently submitted for NCS conservation to improve its appearance after years of neglect and poor storage had led to the development of heavy multicolored surface-obscuring residues. When a coin has developed residues this invasive, there are serious concerns about the state of the underlying surfaces as significant permanent damage is frequently the result. Fortunately, that was not the case here. After successful residue removal, this silver coin was revealed to have an even tone fitting of a nearly-hundred-year-old large British coin. This was able to grade numerically with NGC following conservation.

Great Britain 1931 Crown Before conservation Click images to enlarge.

Great Britain 1931 Crown After conservation Click images to enlarge.

While many residues have specific causes such as PVC, some are of an unknown provenance. This large silver 1810 Peru 8 Reales was submitted to remove residues in general but most specifically the heavy thick light-colored residue obscuring the central reverse. The nature of unusual residues can vary, so care must be taken in their removal. Luckily for this important South American silver coin, the residues were able to be safely removed, revealing mildly toned circulated example. This coin was able to grade numerically with NGC following the professional conservation.

Peru 1810 8 Reales Before conservation Click images to enlarge.

Peru 1810 8 Reales After conservation Click images to enlarge.

Questionable residues can form on more modern coins just as they can on their classic counterparts. This copper nickel 1972-S Proof Kennedy Half Dollar was recently sent to NCS to address a residue that had developed obscuring the reflective fields. As with any Proof coin, additional care must be taken in order to prevent damage to the delicate reflective surfaces during the removal process. All residues were able to be removed to reveal a reflective Proof coin. Following professional conservation, this coin was able to grade well with NGC.

1972-S Proof Kennedy Half Dollar Before conservation Click images to enlarge.

1972-S Proof Kennedy Half Dollar After conservation Click images to enlarge.

For more information about NCS, visit NGCcoin.com/NCS.