NCS Conservation: February Highlights

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.

Small raised green corrosion spots are frequently found on many European medieval silver coins. This Poland-Lithuania 1582 3 Grosz came to NCS featuring some attractive toning and heavy green corrosion spots. While not always possible, the goal is to keep attractive toning while eliminating any surface residues or corrosion. Luckily for this coin, the green spots were able to be removed leaving little scar on the original surface. Following NCS conservation, this coin was able to grade numerically with NGC.

Poland-Lithuania 1582 3 Grosz Before conservation Click images to enlarge.

Poland-Lithuania 1582 3 Grosz After conservation Click images to enlarge.

While many types of residues are seen on similar coins over and over, coins with more history behind them can frequently develop more unusual residues. This large silver English Half Crown dated 1551 had acquired a peculiar red residue in the crevices of its design. Careful conservation work was required to remove this offending reddish hued residue as well as some of the other smaller residues that gave the piece a mottled appearance. The result after conservation is a evenly toned important stately English silver Crown. While the large scratch on the obverse of this coin prevented it from grading numerically, this piece was able to be authenticated and given a proper details grade.

England 1551 Half Crown Before conservation Click images to enlarge.

England 1551 Half Crown After conservation Click images to enlarge.

Just as with more modern issues, earlier coins can develop residues related to long-term storage in less-than-ideal holders. This 1692KB Hungary silver 15 Krajczar had spent quite a long period of time in a flip containing PVC to develop a thick green residue. The PVC residue had become so advanced that bright jade-like stripes of PVC residue can be seen behind the King's head. The conservators at NCS were able to remove the green residue from the entire surface of this coin to reveal a luckily damage-free surface. Following PVC residue removal by the professional conservators at NCS, the coin was able to grade with NGC.

Hungary 1692KB Silver 15 Krajczar Before conservation Click images to enlarge.

Hungary 1692KB Silver 15 Krajczar After conservation Click images to enlarge.

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