From time to time you need to clean the dirt from the coin - it is enough to wash each coin in warm soapy water, taking advantage of the soft brush.Remove all traces of oxidation with coins a bit more complicated than simply wash away the dirt.When removing the oxidation must take into account the nature of the metal of the coin.Gold coins are simply rinse thoroughly in warm water.High-grade silver purified special tool called zilbertaushbader.In its absence, it can use a solution of ammonia.Silver low sample can be effectively cleaned by immersing coin in lemon juice for three to four hours.Another simple and fast way to clean silver - coins rubbing gruel of wet baking soda.Clean copper coins can be a 10% solution of acetic acid (however, normal household vinegar is also nice

).It is necessary to immerse the copper coin in the solution for a few minutes (if the coin is not very strongly oxidized) or for a few hours (if traces of oxidation pronounced).If a coin was formed green plyonochku that numismatists commonly called "verdigris" (on the basis of oxide of copper acetate), it is better to give it to the expert - to clean yourself copperhead is almost impossible.But the noble patina of copper removed is not recommended - it does not spoil the coin, on the contrary, help it last longer maintained.Many numismatists consider the presence of the patina on the coin evidence of its authenticity.Coins of iron and zinc cleaned very carefully, using washing in dilute hydrochloric acid.Rust or plaque with such coins should be removed with the tip of a scalpel or a knife, in the extreme case - brushed brass wire.Cleaning coin hydrochloric acid, try to make the solution less concentrated as possible as too concentrated solution is able to damage the image on the coin.Coins made of aluminum, tin or lead, it is not necessary to clean the aggressive chemicals.For cleaning use cloth or felt, and a small dirt removed the so-called "glass brush."Coins from any metal after cleaning rinse with copious amounts of warm, and then - with cold water and wipe dry.