Exact ‘red’ detail to look for on the front of a Lincoln penny to make it worth $20K – but you need a certain ‘grade’

A RARE penny recently sold at auction for over $20,000 - and if you look for the valuable detail you could cash out too.

The rare coin’s extraordinary value came from its brighter-than-ordinary red color.

It looks mostly like an ordinary Lincoln penny at first glance.

But the color is unusually pigmented.

Plus, it’s very old, dating back to 1909.

The old penny sold at auction for $20,400 on August 14, according to auctioneering website Heritage Auctions.

This particular 1909 cent is a “proof” coin.

Proof coins are some of the first coins minted of a given series.

They’re made with higher quality to show off the design, and they’re often kept for ceremonial or archival purposes.

The red is the hue of “fresh copper,” according to the Professional Coin Grading Service, or PCGS.

It’s hard to keep a coin with its fresh color as copper oxidizes easily.

“Because of copper’s propensity to darken over the years, only very small fractions of old copper coins are found with coloration that would… be deemed 'Red,” PCGS’ website says.

That makes the red color particularly valuable to collectors.

It’s also valuable because of its overall high quality as a proof coin.

It was graded a 67 on a 70-point scale.

How coins are graded

Coins are graded on a scale of one to 70, with one being the poorest grade, and 70 being the most pristine example.

Numbers 60 to 70 are generally the most sought-after by collectors and are known as Mint State coins.

Pieces that fetch thousands at auction are commonly found in MS67, MS68, and MS69 conditions.

An MS-70 is near-impossible to find among older coins.

There are a variety of factors that can make coins valuable, including some strange coins that may be in your piggy bank.

One uncommon nickel could be worth $300,000.

That’s thanks to a “doubling” error creating an unusual pattern.

An old dime sold for $632,000 thanks to its “golden brown” color.

That one could be hard to find, however — it’s from 1804.

A 1919 dime could be worth over $200,000.