First of all, to avoid direct bumping and rubbing with hard objects, do not put several coins in one pocket at the same time. Instead , we need to wrap them in softer cloth or paper.
Secondly, it is necessary to prevent hand stains. The commemorative coins are shipped with a thin transparent plastic bag to protect the surface of the coin from oxidation. Don't take it out and touch it directly. If necessary, wear the thin glove and use your thumb and forefinger to pinch the edge of the commemorative coin to prevent sweat from contaminating the coin. Again, avoid contact with acidic materials.
Thirdly, commemorative coins should be stored in a ventilated, dry place.
The maintenance method of precious metal commemorative coins
should be more strictly as follows:
1. The method of cleaning gold coins. Actually the gold coins do not need to be cleaned. If it is dirty, just wash it in warm soapy water, then rinse it with water and put it in two quick and soft cloths to absorb the water.
2. The method of cleaning silver coins. Firstly, it depends on the oxidation degree and color. If it is high silver content and only slightly oxidized, we'd best to use a solution of sodium carbonate plus sodium carbonate solution and toothpaste to clean; or use white vinegar with a small amount of water, soak the silver coin in its solution for a few minutes; or gently wipe the surface of by cotton ball with the solution, after the oxide layer is dissolved, rinse it off with water.