Why do pennies turn black?

When oxygen binds with copper, they form a new molecule known as copper oxide. Copper oxide is brownish or sometimes black in color (depending on other things in the penny's environment). This is why most pennies you see look dirty or tarnished—it's not actually dirt but copper oxide that makes them look so dull.
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How do you clean a black penny?

Start by adding a quarter cup of white vinegar, or lemon juice, into a cup or glass. Mix a teaspoon of salt into the liquid by stirring until it is dissolved. Place your pennies at the bottom of the cup or glass so that they are not stacked on top of each other. Wait about five minutes and check your pennies.
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Why does a penny change color?

The change from green to black is a sign of progressive corrosion. It occurs when the copper-hydroxide-carbonate on the penny's surface reacts further with oxygen and moisture in the air to form copper sulfides. Older pennies may never reach this level of corrosion and thus maintain a lighter green coat.
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How do you keep pennies from tarnishing?

If you want to protect your copper while it is still new and shiny, clean any oil or other contaminants from the metal. This can be done by simply wiping the metal with a solvent cleaner like xylene or denatured alcohol which can be purchased at most hardware or paint stores.
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What can I do with corroded pennies?

Here is a simple and easy way of cleaning regular corroded coins at home:
  1. Thoroughly wet and clean the coin with clean water – do not completely dump then in water. ...
  2. Roll the wet coin in baking soda.
  3. Using the toothbrush from before, scrub the corrosion away. ...
  4. Rinse the coin – do not soak.
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What if there was a black hole in your pocket?



How do professionals clean coins?

Ultrasonic Cleaners

These coins are cleaned by using distilled water with a small amount of detergent in a special vibrating container. Acid based cleaners will eat away at a coin's surface diminishing its value.
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How do you stop copper oxidizing?

Paint Sealer

A quick and easy way to prevent copper from tarnishing is to spray or paint it with a special type of sealer. This sealer is usually readily available in the market and do a very good job of keeping an airtight seal on copper pieces.
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Can you clean coins without losing value?

It is best not to clean rare coins as removing the patina can significantly reduce the value of them. For this reason, most coin hobbyists almost never clean their coins. In fact, 99% of coins do not increase in value after you clean them, but many will be greatly devalued.
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Is a 1929 penny worth anything?

The 1929 penny can be valued from thirty five cents to as high as $135. The worth of the 1929 penny is dependent on its condition, markings it may have, if it has double stamping and where it was minted. If the penny is all worn out, its worth goes down, but if it is still shiny then it can be worth more.
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Why does Coke clean a penny?

The soda cleans the pennies because it contains phosphoric acid. Phosphoric acid breaks down the copper oxygen compound and causes a new layer of the copper to be exposed.
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What does tarnished penny mean?

When oxygen binds with copper, they form a new molecule known as copper oxide. Copper oxide is brownish or sometimes black in color (depending on other things in the penny's environment). This is why most pennies you see look dirty or tarnished—it's not actually dirt but copper oxide that makes them look so dull.
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What is penny corrosion?

A penny doesn't technically “rust.” The copper plating corrodes, resulting in green surface tarnish. The corrosion is from oxidation -- a chemical reaction between the metal and oxygen, water and carbon dioxide in the air. Rust is the term used to describe this process when it happens to iron instead of other metals.
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Can Coke clean coins?

Who would have thought that your favorite soda is also a great cleaning agent? Yes, that refreshing can of Coke that you like to drink by the pool can also clean coins. Coke's phosphoric acid can clean the oxides that cause tarnish and corrosion.
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How much is a 1943 steel penny worth?

Value of a 1943 Steel Penny

They are worth about 10 to 13 cents each in circulated condition and as much as 50 cents or more if uncirculated.
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What are the 15 most valuable pennies?

  • 01 of 16. 1914-S Lincoln Penny. ...
  • 02 of 16. 1944-D Lincoln Penny on a Zinc-Coated Steel Planchet. ...
  • 03 of 16. 1909-S VDB Lincoln Penny. ...
  • 04 of 16. 1872 Indian Head Penny. ...
  • 05 of 16. 1969-S Lincoln Penny–Doubled Die Obverse. ...
  • 06 of 16. 1926-S Lincoln Penny. ...
  • 07 of 16. 1877 Indian Head Penny. ...
  • 08 of 16. 1914-D Lincoln Penny.
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Will vinegar damage coins?

A common ingredient in DIY eco-friendly cleaners, the acetic acid in white vinegar can help wear away the contamination on your coins. Soak your coins in a glass or other non-corrosive container for at least 30 minutes, up to overnight, and then wipe with a clean cloth or scrub gently with an old toothbrush.
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What pennies are the most valuable?

10 Most Valuable Old Pennies and What They're Worth
  1. 1792 Birch Cent - About $2.6 Million. ...
  2. 1943 Bronze Lincoln Penny - About $1.7 Million. ...
  3. 1793 Strawberry Leaf Cent - About $863,000. ...
  4. 1793 Liberty Cap Wreath Cent - About $391,000. ...
  5. 1944 Steel Lincoln Penny - About $375,000. ...
  6. 1958 Double Die Lincoln Penny - About $336,000.
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How do you make pennies shiny?

Vinegar is a very weak acid on its own, but mixing vinegar and salt creates a slightly stronger acid that will eat away all the copper oxide, and leave you with a nice, shiny penny!
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How do you keep copper from turning black?

Coat the copper item in a protective coating to prevent future discoloration. Coat the item in beeswax or carnauba wax. Dip the soft cloth in the wax and apply it to the copper surface. Buff with a clean soft cloth.
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Can you reverse copper oxidation?

Mix 1/4 cup salt, 1/4 cup flour and enough vinegar to make a thick paste. Use a soft cloth to rub the paste on the surface of the copper. Buff the copper item until it shines. Rinse with warm water and dry thoroughly.
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Why are cleaned coins worth less?

This is because anything that touches a coin has the potential to damage it at the microscopic level. The more abrasive a cleaner is used to clean the coin, the more likely it is to remove the upper surface of the coin - damage that can never be undone.
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Should you clean old coins before selling them?

Don't clean your coins! Not only does this cut their value by as much as half (or possibly even more), but it will be an immediate deal-breaker for many dealers who would've otherwise wanted to buy your coins if only they were left in their original condition.
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How much is the 1969 s penny worth?

Circulated 1969-S doubled die cents are generally worth $10,000 USD and up, while uncirculated specimens typically sell for $35,000 to $50,000 or more.
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