NCS Conservation: November Highlights

Posted on 11/10/2020

See how the removal of detrimental residues improves the appearance of coins and prevents permanent damage.

Numismatic Conservation Services™ (NCS®) uses a variety of proprietary techniques to remove harmful surface 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 Corporation® (NGC®), an independent affiliate of NCS, for grading and encapsulation.

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

Proper coin holders are intended to help protect a coin, but other amateur display methods can do quite the opposite. This Netherlands 1897 Gold 10 Guilder arrived at NCS with the remnants of adhesive clearly obscuring and yellowing the reverse. Often, when a coin is submitted to NCS because of adhesive residue, it is the result of an amateur attempt, often by non-numismatists, to display a coin. Adhesive can react with the surface metal resulting in sometimes-permanent damage. Conservators at NCS have been able to carefully remove adhesive residues from the surface of many types of coins. Fortunately, the residue had not permanently damaged the surface and this gold Dutch coin was able to grade very well with NGC after professional conservation.

Netherlands 1897 Gold 10 Guilder
Before conservation
Click images to enlarge.

Netherlands 1897 Gold 10 Guilder
After conservation
Click images to enlarge.

Long storage in poorer-quality holders frequently causes the development of detrimental residues. This Indonesia 1970 Gold 10,000 Rupiah in Proof strike was submitted to NCS in order to address a mottled opaque residue hiding the reflective fields in tiny dull spots. Residues such as this are often the result of long-term storage in poor-quality holders. Care must be taken to remove the ugly residue on modern Proof coins without damaging the fragile mirrored surface. After professional conservation, this coin was able to grade well with NGC.

Indonesia 1970 Gold 10,000 Rupiah Proof
Before conservation
Click images to enlarge.

Indonesia 1970 Gold 10,000 Rupiah Proof
After conservation
Click images to enlarge.

Spots can be a distracting nuisance on many coins. This France 1901 Gold 20 Francs was recently sent to NCS to see if several spots on the obverse could be removed. Spot removal is a frequent request of NCS conservators, and often success will depend on the nature of the spot in question. On gold coins, small raised spots such as those that appear on this French piece can usually be removed without damaging the surface metal. After careful removal of the offending spots, this coin was able to grade numerically with NGC.

France 1901 Gold 20 Francs
Before conservation
Click images to enlarge.

France 1901 Gold 20 Francs
After conservation
Click images to enlarge.

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




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