Wheat Penny Copper Color is a Key Determinant of Their Value

Copper is considered to be one of the most chemically volatile metals, which means it reacts through the process known as oxidation, which is a chemical process in which the states of atoms are changed when copper comes in contact with air. Oxidation is especially sensitive to moist or humid environments and to the presence of chemicals such as sulfur, which was often present in old coin albums.

Because of this scientific process, copper coins begin to change in color immediately after they are struck. But the degree to which they change, and how quickly they change, will vary greatly depending on a variety of factors such as where and how the coins are stored; how much copper is in the particular coin and what other metals it is made of; and what the source of the copper for the planchets was.

Understanding the main colors that numismatists apply to U.S. copper coins is a critical issue for collectors of those coins whether they collect half cents, large cents like Draped Bust and Classic Head coins, small cents like Flying Eagle and Indian Head and Lincoln cents or two cent coins.

But while older U.S. copper coins mostly are made from copper that copper was obtained from different sources, which means different coins have varying amounts of impurities in them that also play a role in the particular color of those copper coins.

And when it comes to the most widely collected cents – the always popular Lincoln penny – those coins were made of 95% copper until 1982 except for the zinc-plated steel cents issued in 1943 during World War II when copper was needed for armaments. (Even then, a couple 1943 bronze cents and copper 1943 Lincoln cents slipped through) And pennies struck since 1982 are copper-plated zinc with just 2.5 copper and the rest being zinc.

The vast majority of circulated copper coins, especially older pieces large half and large cents are brown or black in color because they have had so much time to oxidize and because collectors in say the 19^th century did not have the storage methods available today.

When it comes to ancient coins especially those that are bronze they have oxidized so much that they are typically green in appearance or have another color such as olive, magenta, etc.

In addition to the general rule that all coin collections should be stored in as dry and cool an environment as possible, it is also important to be careful what kind of holders or albums coins are stored in.

In addition, coins professionally graded such as by PCGS and NGC are placed into holders known as slabs that with the most recent improvements are now almost 100% inert. And NGC will guarantee that the color of a copper, bronze or copper-nickel coin in one of its holders will not change for 10 years from the time it grades the coin.

Color Scheme

When it comes to uncirculated copper coins or coins that have at least some copper in them, numismatists have established a scheme that consists of three main colors: Red (RD, Red-Brown (RB) and Brown (BN). And those colors play a critical role in the value of copper coins as well as their eye appeal for collectors.

A lot of coins have a color that does not always neatly fit within one of those designations but to aid collectors and coin graders, NGC states that red coins will have at least 85% of their red luster while Red-Brown coins have at least 15% of that red luster. Any coin with less red than 15% is considered Brown.

PCGS states that Red coins are those that grade MS60 or higher that have 95% or more of their original red color; Red-Brown are mint state coins that have between 5% and 95% of their original mint red color; and Brown coins have less than 5% of their original color.

When it comes to which color collectors prefer, that is a subjective matter as some collectors might prefer RB coins because they fit in with the rest of their collection even though RD examples are almost always valued more highly than coins of the other two colors.

Because fully or close to fully Red coins are so scarce, especially for early American copper coins, they are prized and valued very highly. In fact if two copper coins are perhaps a grade apart from each other, a RD example a grade lower is usually worth more than a RB or BN example at the higher grade. But this will depend on how much different in grades exists and on the particular coin and series.

Also, when it comes to for example Lincoln cents struck before 1934 that have been given the RD designation, they will look very different from a modern Lincoln penny that is RD. The older ones are likely to have anything from a red-pink to red-yellow or red-orange color and everything in between. For this reason, it is helpful to see as many such coins as you can such as by attending large coin shows or visiting local coin dealers.

And there are other surface issues that should be considered too such the presence of carbon spots. Virtually any mint state copper cent with original RD color will have at least some minor spots of this type, but if they are a lot more prevalent, that will detract from the coin’s value.

Finally, there is also the issue of artificial toning of coins to give them a certain appearance, which can be done by doing things like placing them for an extended period in an older coin album. Experienced numismatists can tell the difference between natural coloring on coins and those that have been doctored in some way.

So spend time getting to know the color of your money, especially your copper coins!