What causes white spots to develop on modern silver coins?
Planchets, the round disks that are struck into coins, are usually washed after they are made. This helps to remove any contaminants and give the planchet a brighter appearance.
It is believed that if the planchets are not completely rinsed, the remnants of the solution used to wash them will cause white spots to develop over time. This has not been proven, however, and world mints do not seem to be able to prevent these white spots from developing.
How do I know if my modern silver coin will develop white spots?
There is no known method to determine whether a modern silver coin will develop white spots, or how large these spots will be. Some modern silver coins never develop white spots. Others develop white spots immediately after they are struck. The development of white spots appears to be entirely unpredictable.
Can white spots develop after the coin is encapsulated in NGC’s holder?
It is possible that white spots can still develop after a modern silver coin is encapsulated in NGC’s holder. Many collectors and dealers claim that modern silver coins spot less frequently after they are encapsulated in NGC’s holder and that the NGC holder is the best for preventing the development of white spots. These claims have not been scientifically verified, however, and any such evidence is purely anecdotal.
Do white spots affect the NGC grade?
NGC will factor white spots into its grading of modern silver coins just as it does for black spots on copper coins and red spots on gold coins. Larger and more distracting spots will result in lower grades. Heavily spotted coins may receive an NGC Details Grade with an Environmental Damage notation.
The development of white spots after a coin is graded by NGC is not covered under the NGC Guarantee because these white spots occur unpredictably and through no fault of NGC’s. If an NGC-certified modern silver coin develops white spots, NGC will leave it in its original holder or reholder it with the original grade.
Do white spots affect the value of modern silver coins?
NGC does not buy or sell coins and does not track the difference in prices paid for spotted and unspotted modern silver coins, if any. Prospective buyers of modern silver coins are encouraged to research prices, consult with market experts and determine their own comfort level for coins that have or may develop white spots.
Can professional conservation from NCS remove white spots?
Numismatic Conservation Services (NCS), an independent affiliate of NGC, has conducted extensive research but has been unable to determine a conservation technique that can prevent or remove white spots without damaging the coin. In some cases white spots can be minimized, but they cannot be removed.