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What are coins made of?
Penny, nickel, penny, dime! You might use them to buy bus or subway tickets, or collect them as change at the grocery store. Although coins might look copper or silver, what are they really made of?
Well, until 1965, quarters and nickels really were made mostly of silver. Nickels, dimes, quarters, and half dollars are primarily made up of the same compounds in similar concentrations, and differ only in their size and weight. All four coins are more than three-fourths copper, despite their silvery hue. The rest of the coin is made up of nickel (the element, not the denomination). Interestingly, some coins are more expensive to make than they are worth! A nickel costs 9.4 cents to make. Dimes, quarters, and half dollars range from 4.6 cents to 11 cents in production costs.
The penny is another coin that might be more trouble than it’s worth, costing 2.6 cents to make! Our smallest coin is zinc on the inside and covered by a very thin layer of copper. If you scrape off the thin outermost layer, the interior is a dark gray.
Dollar coins are unique. They are also made of copper, zinc, and nickel. However, they also contain another metal known as manganese. This unique alloy is what creates that characteristic golden-brown hue that makes them so easy to spot in your wallet.
What are notes made of?
Have you ever wondered how many people have used the note that you’re holding? It may have been used by dozens, or even hundreds of people before ending up in your hands. If you tried something similar with a piece of notebook paper, or even a plastic-coated receipt, you’d find it would disintegrate pretty soon. If you’ve ever had the misfortune of getting rained on while holding your wallet, you may notice the notes dry off pretty quickly. They can withstand a little bit of water, or wet hands handling them. How are notes so durable?
In addition to durability, notes also need to be hard to duplicate, or counterfeit . If dollar bills were easy to print, everyone would be making copies of them! The U.S. Federal Reserve needs to create bills that are difficult to replicate using ordinarily accessible materials.
Despite looking like paper, dollar bills are actually made of 75% cotton and 25% linen. This is what gives them that papery texture, without the fragility that comes with paper. On average, a dollar bill remains in circulation for almost seven years before it is retired! A hundred dollar bill tends to be used far less frequently, so it stays in circulation an average of 22 years before it is retired!
In addition to the cloth-like material, notes also use special ink. The ink shifts color from copper to green. Holding up a note to the light and seeing if there is a shift in color is often the fastest way to identify a counterfeit bill. Genuine bills also have tiny red and blue fibers scattered throughout that are visible under a magnifying glass. The security thread woven into the bill also glows under UV light! Each denomination glows a different color. Replicating the color changing ink and UV-activated thread is a tough task indeed.
The U.S. Federal Reserve has extensively researched the best materials to make coins and notes. Next time you use cash, check for all these fascinating features!
Glossary
Counterfeit: A fraudulent imitation of something else, particularly coins or money.
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