Residues can be not only unattractive but, when left on the surface of a coin, can lead to permanent changes to a coin’s surface.
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.
Residues can be not only unattractive but, when left on the surface of a coin, can lead to permanent changes to a coin’s surface. Professional conservation can help to both remove the unattractive residue and prevent any surface damage from occurring.
A silver 1986 Switzerland ounce specimen was recently submitted for NCS conservation to improve its appearance by removing an uneven hazy residue that had formed on both sides of the coin. Hazy residues such as these can be troublesome to remove carefully without leaving hairlines. However, the professional conservators at NCS have developed techniques to remove these residues safely. After successful PVC residue removal, this special coin was revealed to be bright and subsequently able to grade very well with NGC.
Many modern coins develop residues that are often a result of original mint packaging. Residues that form in this fashion are often particularly noticeable on Proof coins. A gold Isle of Man five-Sovereign was submitted to remove a substantial opaque hazing residue hiding the reflective surfaces. It is important to remove these kinds of residues carefully without disturbing the reflective surfaces of a Proof coin underneath. Luckily all residues were able to be safely removed, allowing this coin to grade very well with NGC.
Not only do specially issued modern coins often develop unattractive residues through poor storage, but those made for circulation can just as well. A copper nickel clad 1971-D Eisenhower dollar was recently sent to NCS to address an exceptionally heavy residue that had developed, giving the coin an unusual color. Heavy residues such as this are often due to long-term storage in less-than-ideal standards that may have included a coin holder containing PVC. Luckily, the offending residues were able to be slowly removed, revealing an evenly natural-colored nickel alloy coin with little permanent surface damage. Following professional conservation, this coin was able to grade well with NGC.
For more information about NCS, visit NGCcoin.com/NCS.
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Press release courtesy of the Numismatic Guaranty Company