NGC Conservation: Residue Is No Match for NGC's Conservators

Numismatic Guaranty Company® (NGC®) 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, they are then graded and encapsulated. Below are a few highlights of coins that were conserved and graded by NGC recently.

1984-S Olympic Commemorative Silver Dollar

Some residues have tell-tale features that indicate how they likely occurred; while other extreme kinds of residues can form through unknown storage conditions that can be just as detrimental. This 1984-S Olympic Commemorative Silver Dollar was recently submitted to safely remove a heavy opaque residue that had completely covered the coin in a disgraceful way. Heavy residues on modern coins can damage the surface underneath, making their removal important both aesthetically and to promote future stability. Care must be taken when removing heavy residues from Proof coin surfaces as to not cause further damage to the fragile mirrored fields. After professional conservation work, this commemorative was found to be free of permanent damage and went on to grade well.

1984-S Olympic Commemorative Silver Dollar Before conservation Click images to enlarge.

1984-S Olympic Commemorative Silver Dollar After conservation Click images to enlarge.

1851 Gold Dollar

Coins can be subjected to some unusual storage schemes. Often, the poorest storage schemes can leave strange evidence on a coin laser. This diminutive 1851 Gold Dollar was submitted to NGC to remove a dark orange raised residue splashed across the obverse. The residue appears to be the remnants of glue, which is often found on the surface of a coin coming from poor storage — such as when transparent tape or liquid glue is used to affix a coin to something by a novice collector. The NGC conservators are well practiced in removing these types of adhesives without damaging the surface underneath. Luckily, the glue was removed from this coin before the residue had begun to cause permanent damage. After removal, this gold coin was revealed to be bright and was able to grade well.

1851 Gold Dollar Before conservation Click images to enlarge.

1851 Gold Dollar After conservation Click images to enlarge.

1935 Spanish Trail Commemorative Half Dollar

After decades of poor long-term storage have left marks on coins, conservation can help bring back their true beauty. This silver 1935 Spanish Trail Commemorative Half Dollar had developed a residue in stark, opaque spots across both sides. Poor storage conditions likely led to the development of these heavy spots. The professional conservators at NGC have techniques to remove the residue blight and return the coin to a bright example of this popular commemorative. The coin was able to grade numerically following conservation.

1935 Spanish Trail Commemorative Half Dollar Before conservation Click images to enlarge.

1935 Spanish Trail Commemorative Half Dollar After conservation Click images to enlarge.

For more information about NGC Conservation, visit NGCcoin.com/ngc-conservation.