NCS Conservation: Coins from Asia Benefit from Residue Removal

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.

Long-term storage in soft flips containing PVC will lead to the formation of some unattractive residues. These types of residues can lead to permanent changes to a coin surface in the form of corrosion. Professional conservation can help to both remove the unattractive residue and prevent any surface damage from occurring.

This silver China 1983 Panda 10 Yuan was recently submitted for NCS conservation to improve the appearance by removing a thick uniform residue that had formed on both sides of the coin. Hazy residues such as these can be troublesome to remove carefully without leaving hairlines although the professional conservators at NCS have developed techniques to remove these residues safely. After successful PVC residue removal, this coin was revealed to be bright and subsequently able to grade very well with NGC.

China 1983 Panda 10 Yuan Before conservation Click images to enlarge.

China 1983 Panda 10 Yuan After conservation Click images to enlarge.

Many modern coins develop residues that are often a result of original mint packaging. A combination of a lack of air-tight design and use of questionable materials can lead to the formation of unattractive residues. This silver with gilt details 2002 Hong Kong $50 was submitted to remove an uneven opaque hazing residue hiding the reflective surfaces. It is important to remove these kinds of residues carefully without disturbing the golden gilt details. Following professional conservation to remove the obscuring residue, this coin was able to grade very well with NGC.

Hong Kong 2002 $50 Before conservation Click images to enlarge.

Hong Kong 2002 $50 After conservation Click images to enlarge.

Modern coins often develop unattractive residues through poor storage. This copper nickel 1972 proof Malaysia 1 Ringgit was recently sent to NCS to address an exceptionally heavy residue that had developed to the point of completely obscuring the reflective fields. Heavy residues such as this are often due to long-term storage in less than ideal standards that most likely included a coin holder containing PVC.

There is always a great deal of concern over what the surfaces look like underneath when a coin comes to conservation with this advanced state of residue development. Luckily, the offending residues were able to be slowly removed revealing a bright reflective proof coin with little permanent surface damage. Following professional conservation this coin was able to grade well with NGC.

Malaysia 1972 Proof 1 Ringgit Before conservation Click images to enlarge.

Malaysia 1972 Proof 1 Ringgit After conservation Click images to enlarge.

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