A full red copper coin is a coin that displays most or all of its original red copper color.
Of the criteria used to assign a grade to coins, color is added to describe cents. This is used for all U.S. Mint copper coinage, which includes Mint State and Proof varieties of large cents, half cents, small cents, two cents, and select pattern coins.
What Causes a Cent to Change Color?
To demonstrate the potential for copper to change color, consider the Statue of Liberty, which was once brown and turned green after a mere three decades of exposure to sea air. Like Liberty’s Statue, copper coinage reacts to gases in their environment.
Brand new copper planchets and coins are orange or orange-red colored. They begin changing from this bright and warm color the moment they meet air and begin reacting to gases in the air.
As the copper in a cent is exposed to gases in the air, it oxidizes. Sulfurs like hydrogen, carbonyl, and dimethyl are said to cause various toning and patina on copper. This oxidation deposits a layer of copper oxide on the surface of the coin and often appears as a patina or tarnish.
How Does Color Affect Coin Grading?
Coins are graded on a number of factors, like the sharpness of the strike, the preservation of details, remaining mint luster, and more. With copper coins like U.S. pennies, color is graded as well. The three colors used for grading pennies are red, red-brown, and brown.
How Do Grading Organizations Assess Red Pennies?
As with many designations and strike characters, there are similarities between the primary grading organizations, but their standards are not identical.
First, we will cover the Professional Coin Grading Service (PCGS) standards for Red cents, and then we will go over the same standards for the Numismatic Guarantee Corporation (NGC).
PCGS Standards for Red Cents
For a cent to be eligible for a Red (Rd) strike from PCGS, it must receive an adjectival grade of MS-60 or greater. Cents with an MS-60 or greater score and display 95% or more original red mint color.
NGC Standards for Red Cents
To obtain a Red strike character from NGC, a cent or copper coin must exhibit 85% of its original mint red luster. This is a cent in which there is no noticeable brown among the red copper on the designs or in the fields.
Are Red Pennies Worth More?
If we are comparing two identical cents from the same year and mint, with both receiving the same Mint State Sheldon grade, the red penny should be worth more. This is due to the preserved mint state color.
It is worth keeping in mind that the relative rarity of a coin is chief among the factors that demand a higher premium.
