When and how to clean coins?
It isn’t just coin collectors who are concerned about keeping their valuable pieces in good condition – anyone who owns special coins naturally wants these beautiful objects to stay looking at their best. With this in mind, we’ve put together some tips and tricks for cleaning and looking after your coins.
Proper cleaning, care, conservation and storage is an integral part of coin collecting. Cleaning in the wrong way, for example using metal cleaning or scouring agents and sharp-edged or pointed tools, could significantly devalue the coins or even render them totally worthless.
Careful cleaning of soiled coins can enhance their appearance. However, it will not affect their grade, which cannot be improved by cleaning. Proper storage is more effective in this regard, and could even make cleaning unnecessary. Storage encompasses both packaging, e.g. coin capsules, presentation cases or coin boxes (NB: avoid plastic sleeves as these contain softening chemicals called plasticisers), and ambient conditions: the room should be neither too hot nor too cold.
Exercise care and restraint when cleaning
Gold and platinum are coinage metals that rarely oxidise, and only with difficulty. Consequently, coins made from these metals do not usually need to be cleaned. With silver coins, a coating of silver sulphide can build up over a period of years. This is known as a patina. An old coin with a natural patina should not be cleaned and the patina should not be removed, as this would cause the coin to lose some or all of its value.
Before cleaning your collector’s pieces, it is important to ascertain what metal or alloy the coins are made of, whether treatment of any kind is advisable, and if so, how to avoid causing irreparable damage to these miniature works of art. As a general rule, coins should be cleaned as little as possible, especially those of proof quality.