Think about the number of times you’ve handled a quarter. You’ve slipped them into parking meters, stacked them on counters, or even flipped one to settle a debate. They’re so ordinary that most of us never stop to look at them closely. But if you run your thumb along the edge of a quarter, you’ll notice something: tiny ridges, perfectly cut and neatly aligned.

At first glance, these ridges might seem like nothing more than decoration or a way to make coins easier to grip. But the truth is far more fascinating. These grooves have a history stretching back more than 300 years, born out of crime, ingenuity, and the need to protect entire economies from collapse.

The Crime That Sparked Coin Ridges

Back in the 17th century, coins weren’t made of inexpensive metals like they are today. Instead, they were minted from silver and gold, giving them real intrinsic value. This opened the door for a clever kind of theft known as “coin clipping.”

Coin clippers were thieves who shaved tiny slivers of metal off the edges of coins. These shavings, though minuscule on their own, could be melted down and collected into valuable bullion. Meanwhile, the clipped coins were still passed off at full value because the missing metal was difficult to detect at a glance.

One coin here or there didn’t make much difference. But when done systematically, clipping threatened to drain precious metals from circulation and destabilize the entire economy. The practice became so widespread that governments were desperate for a solution.

Enter Isaac Newton: The Mint’s Secret Weapon

Yes, that Isaac Newton. Known to the world as the genius behind the laws of motion and gravity, Newton was also appointed Warden of the Royal Mint in England in 1696. And among his first tasks was to put an end to coin clipping.

Newton’s solution was simple but brilliant: give coins ridged, or “reeded,” edges. With these grooves in place, clipping became immediately obvious. Any coin that had been tampered with would show broken or uneven ridges, while an untampered coin displayed perfect, continuous grooves. At the time, no counterfeiter could replicate the mint’s precise reeding pattern.

This was 17th-century security technology at its finest. And it worked. Newton not only introduced ridged coins but also personally oversaw the prosecution of more than a hundred counterfeiters. Some of them faced severe punishment, sending a clear message that coin tampering would no longer be tolerated.

Why Coins Still Have Ridges Today

Fast forward to the present day. Most coins no longer contain silver or gold. Modern quarters and dimes are made of copper-nickel, and pennies are mostly zinc. So why do ridges still exist? The answer lies in a mix of tradition, security, and accessibility.

1. Security Against Counterfeiting
Even now, ridges are part of a coin’s security profile. Counterfeiters still struggle to replicate the exact number, spacing, and depth of ridges. On top of that, vending machines and banking equipment often scan a coin’s edge to confirm its authenticity.

2. Accessibility for the Visually Impaired
Ridges aren’t just for machines—they’re for people, too. For those who are blind or visually impaired, the texture of a coin provides an easy way to tell denominations apart. A smooth-edged nickel feels completely different from a ridged dime or quarter, making everyday transactions more inclusive.

3. Tradition and Familiarity
Finally, ridges have simply become part of what we expect from coins. They sound different when they clink together, they roll differently across a surface, and they feel distinct in your hand. In a world where most payments happen digitally, those small tactile details keep physical money feeling like “real” money.

Why Some Coins Don’t Have Ridges

If you’ve ever wondered why pennies and nickels are smooth while dimes and quarters are ridged, the explanation lies in history. Pennies and nickels were never made with precious metals, so there was no reason for thieves to clip them. Without any incentive, there was no need for ridged edges.

Quarters, dimes, and half-dollars, on the other hand, once contained silver. Their ridges served as a safeguard against clipping, and even though today’s versions are made of cheaper metals, the tradition of reeded edges has carried on.

Interestingly, half-dollars still have ridges as well—though few people notice since they’re not commonly used in everyday transactions anymore.

The Lasting Impact of Coin Ridges

What started as an anti-theft measure centuries ago is still shaping how we interact with money today. Those ridges aren’t random. They’re a quiet reminder of the battles fought to protect economies from fraud and corruption. They also highlight how a simple design change—something you can feel with your fingertips—helped secure the financial systems of an entire era.

So the next time you hold a quarter, don’t just toss it in a vending machine without a second thought. Take a moment to run your thumb along its edge. Those little grooves carry centuries of history, ingenuity, and resilience in every tiny line.