NCS Conservation: Does Residue Have You Seeing Red?

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.

Even circulated coins can develop unattractive residues. This Australia 1888 gold Sovereign with an M mintmark (indicating the Melbourne mint) was recently submitted for NCS conservation to address the reddish orange residues that had developed on both sides of the coin. Red-colored residues such as this can often be found on circulated gold coins from all over the world. The conservators at NCS have developed special techniques to safely remove these kinds of residues without damage to the delicate surfaces underneath. Following careful conservation work, this early Australian gold piece was able to grade well for a nice circulated example.

Australia 1888 Gold Sovereign Before conservation Click images to enlarge.

Australia 1888 Gold Sovereign After conservation Click images to enlarge.

Detrimental residues can form on the surface of coins held in lesser quality holders. This silver 1941 South Africa Shilling was submitted to NCS because of a heavy greenish white residue obscuring the surface. Residues like this are most often caused by long-term storage in lesser quality PVC flips. Careful conservation work is required to remove the potentially damaging PVC residue while attempting to retain the pleasant peripheral toning of this silver coin. Heavy residues such as what was seen here can often cause permanent damage. Following conservation, this coin was able to grade numerically with NGC.

South Africa 1941 Silver Shilling Before conservation Click images to enlarge.

South Africa 1941 Silver Shilling After conservation Click images to enlarge.

Lower quality coin holders can allow the development of ugly and damaging residues quickly. Proof of this is this relatively recently made 2018 Great Britain bi-metallic commemorative honoring the Royal Airforce. Here is a relatively recently made coin that through storage in poor quality holders has developed a hazing surface obscuring residue. Luckily after the residue was removed no damage was present and this coin was able to grade well with NGC.

Great Britain 2018 Bi-metallic Royal Airforce Commemorative Before conservation Click images to enlarge.

Great Britain 2018 Bi-metallic Royal Airforce Commemorative After conservation Click images to enlarge.

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

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