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Basic Knowledge Of Metal Commemorative COINS
- Oct 05, 2017 -

Usually, gold is corroded by silver; Silver than copper corrosion; Zinc, aluminum, iron and other metals are more vulnerable to corrosion. For alloys, sometimes the chemically active metal, such as pure gold, is better, and when copper is added to gold, it is easy to spot black spots on COINS.


But brass (copper and zinc alloy) is more resistant to corrosion than pure copper in the atmosphere. Packaging material PVC is harmful to the COINS, materials such as water vapor, sulfur and carbon dioxide in the air to coin is very harmful, such as sulfur react with silver into silver sulfide, change the surface of the silver gray to black. Moisture in the air also speeds up the oxidation of COINS. During the process of appreciation, you touch the naked currency with your hand, leaving the sweat on the coin to leave fingerprints on the COINS, and the dust in the saliva and air lands on the coin, which will speed up the process of the coin's corrosion.


Choosing the means of packing is the basic skill of coin collectors. In general, the optional packages include plastic boxes for polyvinyl chloride, paper central, polyester film bags, paper bags, etc. Optional materials are polyethylene, polypropylene, polyester film. Admire to facilitate, but also on the basis of transparent packaging volume into the collection of COINS, the key point is not to choose materials to packaging to store COINS containing polyvinyl chloride (PVC), the harm of it must not be underestimated. In order to isolate the air, there are two ways to encapsulate gas and vacuum.