How To Clean Green Pennies & Coins

How To Clean Green Pennies & Coins

Why Do Pennies Turn Green?

Copper that is exposed to open air will corrode and undergo a series of chemical reactions that lead to the development of a patina – a coating of copper oxide molecules that actually protects the metal beneath. Over time, copper transitions from its shiny brown color to a darker brown shade. This is why Pennies often turn brown before they turn green.

After many years it transitions into blues. At an even later stage the formation of copper sulfate, carbonate and chloride salts in varying concentrations turns the surface green; explaining how pennies turn green. There are several factors that affect the amount of time these processes take including moisture, temperature, and the level of pollution. The formation of the natural green patina seen on copper roofs and statues takes a very long time, but methods have been developed to speed the process up using chemical reactions.

How to Clean Old Pennies

There are several methods available for reverting green pennies back to their former shiny copper glory. To clean about two dozen, stir ¼ cup of white vinegar and 1 teaspoon of salt until the salt dissolves in a non-metallic bowl. Soak the pennies in the mixture for five minutes. Rise really well under running water and place on a paper towel to dry. green penny - lone-old-penny-coinAnother method requires a pencil with a fairly pliable eraser. If the eraser is too hard, it can leave deep scratches in the penny. Place a dirty penny on a clean cloth and rub gently in a circular motion with the eraser. Flip the penny and repeat.

Another cleaning method requires ¼ cup of tomato ketchup, a small container, an old toothbrush and a clean cloth. Dip the toothbrush into the ketchup than scrub the penny, on both sides, gently in a circular motion with the toothbrush. Rinse under warm, running water. Pennies can also be cleaned with soap and water or baking soda.


Cleaning Corroded Old Coins

There are cases, however, when a coin is valuable and only light cleaning is recommended to retain the value of the coin. If you suspect you are in possession of a rare penny, or an old coin which can be worth money, make sure to never touch the face of the coin. Because the cleaning process required to restore the original bright and shiny look of the penny are nearly always abrasive, cleaning them rarely improves the grading of a valuable coin and almost always reduces the value.

A survey of common price discounts on cleaned coins offered by dealers indicates that cleaned coins  scratched through abrasive  processes are rarely worth more than half of their original value before the cleaning. It is generally acceptable to clean corroded coins with dirt on them by soaking briefly in clean water. After removal from the water, pat -don't rub -the coin dry with a soft towel.

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Should You Clean Old Pennies?

Nearly all of us have stashes of pennies throughout our homes and in the ashtrays of our vehicles. And some of those old pennies can be both very rare and very valuable.

A list of the more valuable pennies includes the 1944 Steel Wheat Penny with no mintmark. They are currently valued at more than $77,000 and one in perfect condition can fetch upwards of $110,000.

A 1943 Copper Wheat Penny can get more than $60,000 and one in perfect condition can be worth nearly $86,000. A 1909-S V.D.B. Is valued at $2,250. A 1923 Wheat Penny is valued at $750. A 1909-S can fetch $450. The 1913 D Wheat Penny and 1916 S Wheat Penny are both valued at $225. Should you be cleaning your old coins? If you have the right pennies, you could make a great deal of money. Before you trade those pennies in for cash, take some time to examine them, as they may be valuable. Feel free to check out some of our U.S. Mint coins for sale if you are looking to boost your U.S. coin portfolio.

If you’re interested in reading more about rare US coins, check out some of our other great posts including, ‘Should I Buy Circulated or Uncirculated Coins?’, ‘Why Do Pennies Turn Green? ' and ‘The Most Valuable US Coins in Circulation’.