Proper care is essential for preserving the value of numismatic and rare coins. The following guidance outlines how collectors can handle, clean, maintain, and store valuable pieces responsibly. 
Handling Rare Coins
Rare coins should be lifted only by their edges, never by either face. Natural skin oils can quickly leave permanent fingerprints and/or toning that harm a coin. When practical, use lint-free cotton gloves to pick up or hold valuable coins. Latex and plastic gloves should be avoided because they may contain powders or lubricants that could damage a coin.
When examining a coin, cover nearby hard surfaces with a soft towel or mat to reduce the risk of damage. Store coins in inert plastic holders, including a soft 2 x 2 plastic flip or a rigid plastic capsule, so they are protected from contact, friction, and drops. Choose holders, albums, and cardboard sheets made specifically for coins. Avoid pvc holders, which can deteriorate over time and stick to coins.
Cleaning and Caring for Old Coins
Most coin specialists offer simple guidance about cleaning coins: do not do it. Rubbing, scratching, cleaning, or polishing a coin’s surface may lower its value by as much as 50 percent. If cleaning is necessary, limit it to bullion coins, whose worth comes from metal content rather than collectible or numismatic appeal. Do not use commercial coin cleaners, since they contain materials that remove metal from the surface. Naturally aged coins are more valuable and avoid cleaning damage such as hairline scratches.
For coins coated with dirt or grease, mild dish detergent and distilled water can remove the debris. Rinse the coins, then let them dry in the air. Tap water should not be used because it can harm the coin.
As noted above, high-grade uncirculated and proof coins, along with copper-alloy coins, should never be cleaned by this method or another. Heavily encrusted or corroded coins can be left in olive oil for several months, which may ultimately dissolve the crust. Some third-party grading services, including Numismatic Guaranty Corporation (NGC), also offered conservation services.
When this article was originally published, readers seeking information about older coins or a valuation were invited to rely on Atlanta Gold & Coin Buyers. At the time of publication, Atlanta Gold & Coin reported transparent buying rates and competitive pricing for people buying or selling gold, silver, or platinum coins, plus rare coins, foreign coins, and privately minted bullion. The original article stated sellers could receive a free appraisal in person, online, or by mail. It also invited readers to schedule an in-person appraisal at the Midtown Atlanta or Johns Creek offices by calling 404-236-9744.
