NCS Conservation: PVC You Later!

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.

China 1904 Silver Tael

Green PVC residues form from long-term storage in lesser-quality coin holders and can, with time, begin to damage the surface of a coin. This large China 1904 Silver Tael of Hupeh (Hubei) Province was recently submitted for NCS conservation to address the green PVC residues that had developed in large sections on both sides. The opaque pale green residues are indicative of a coin that has been stored in a holder containing PVC and in which the plasticizer has leached out in unsightly deposits on the coin’s surface.

The conservators at NCS have developed special techniques to remove these kinds of residues without damage to the surfaces underneath. Following careful conservation work, this important Chinese silver coin was free of damaging residues and was able to retain a mild tone fitting a coin of its age. Despite the professional conservation efforts, evidence of old cleaning on this rare piece prevented it from grading numerically with NGC.

China 1904 Hupeh Tael Before conservation Click images to enlarge.

China 1904 Hupeh Tael After conservation Click images to enlarge.

Saudi Arabia AH1370 (1950) Proof Gold Pattern Guinea

Poor-quality coin holders can create very unattractive and potentially damaging residues. This Saudi Arabia AH1370 (1950) Proof Gold Pattern Guinea was submitted to NCS to address the formation of general hazing residue and a large green deposit. The professional conservators at NCS were able to safely remove the green deposit from the surface without inflicting any further damage to the sensitive Proof gold surfaces. Following careful conservation this coin was able to grade well with NGC.

Saudi Arabia AH1370 (1950) Pattern Guinea Before conservation Click images to enlarge.

Saudi Arabia AH1370 (1950) Pattern Guinea After conservation Click images to enlarge.

India VS1985 (1928) Silver Rupee

Long-term storage in soft flips that contain PVC can lead to disastrous results on the surface of any coin held within. This India VS1985 (1928) Silver Rupee of Mewar was submitted to NCS to remove pale green residues that had formed uniformly over both sides. Pale green residues on silver coins, including the one seen here, are often a sign of long-term storage in a holder containing PVC. The NCS conservators are well adept at removing residues such as this and were able to remove all traces safely, leaving a bright white silver coin. This popular Indian coin was able to grade numerically with NGC following successful conservation.

India VS1985 (1928) Mewar Rupee Before conservation Click images to enlarge.

India VS1985 (1928) Mewar Rupee After conservation Click images to enlarge.

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