Toning

Slabs are not completely air tight so whether a coin in a slab will continue to tone depends on the environment in which the coin is stored. If it is subjected to extreme temperature changes and/or high humidity the coin is more likely to be affected. Dry, cool storage most likely will not affect the coin. Ideally you want the coins stored in a place that has a fairly constant low humidity temperature. If you live in the parts of the country which have high humidity and want to keep your coins at home then you should consider placing desiccant in the box or wahtever the coins are stored in to reduce the amount of moisture in the air from affecting the coins.

Ed
ANA LM-3175