Gold Washington Quarter Mint Error – Struck Over an 1898 $5 Gold Coin
Author’s Note: Mint Error News featured this extraordinary gold quarter on the cover of Mint Error News Magazine Issue 66. At that time, NGC graded the coin PF66, and Mike Byers sold it. The coin has since moved into a PCGS Proof-66 holder. GreatCollections will offer the rarity in an auction that closes September 13, 2026.
Most 1970-S Washington Quarters began life as copper-nickel clad planchets.
This one began life as a $5 gold coin from 1898.
That single fact places this spectacular Proof error in a class of its own.
In 1970, Washington Quarter Proof Dies at the San Francisco Mint struck a $5 proof gold coin dated 1898. As a result, John Flanagan’s familiar Quarter design is overstruck on Christian Gobrecht’s 19th-century gold design.
The two coins came from different centuries. They carried different denominations. They used different metals. Even their standard weights differed dramatically.
Yet somehow, 72 years after the Mint produced the $5 gold coin, it entered a Proof coining operation and emerged as a 1970-S Washington Quarter.
GreatCollections now calls the coin “Believed Unique.” PCGS grades it Proof-66. The coin weighs 8.3 grams.
Two Coins Separated by 72 Years
The physical evidence tells the story.
Under magnification, collectors can still read the 1898 date from the underlying Half Eagle on the reverse. It appears above QUARTER DOLLAR. Additional remnants of the Liberty Head Half Eagle design survive beneath the Washington Quarter design on both sides.
That surviving detail makes the error especially dramatic.
The dies overstruck an already coined United States Half Eagle.
The weight provides another powerful clue.
A standard 1970-S Proof Washington Quarter weighs 5.67 grams. PCGS lists its normal composition as an outer alloy of 75% copper and 25% nickel bonded to a pure copper core. The standard coin measures 24.30 mm in diameter.
By contrast, PCGS lists the standard 1898 Liberty Head Half Eagle at 8.36 grams, with a composition of 90% gold and 10% copper. The Half Eagle measures 21.65 mm.
The error weighs 8.3 grams.
In other words, its weight closely follows the original $5 gold host rather than a normal 1970-S quarter planchet.
How Does a 19th-Century Gold Coin Reach a 1970 Proof Press?
That question gives this coin much of its mystique.
The San Francisco facility handled Proof production during this era. Moreover, Proof coinage required far greater control than ordinary circulating production. The U.S. Mint describes Proof coins as special coins made with highly polished planchets and dies. The Mint also notes that Proof coins often receive more than one strike to bring out the design.
My original Mint Error News account also emphasized the hands-on nature of Proof production. Technicians fed blanks into special presses, then workers examined and packaged the finished coins under strict quality controls. Other major Proof errors exist, including broadstrikes, off-center strikes, double strikes, and off-metal pieces. Some have even surfaced in sealed Proof sets.
Therefore, a major Proof error already attracts attention.
A Proof quarter overstruck on a decades-old gold coin moves into another category altogether.
The sources reviewed for this article do not document exactly how the 1898 Half Eagle entered the 1970 Proof production line. The coin itself, however, preserves the result.
The California Proof Error Connection
There is another remarkable chapter to the story.
In my original coverage, I discussed a group of several hundred U.S. error coins that surfaced from a safe-deposit box in the early 2000s. The group included Proof errors as well as errors involving coins intended for circulation.
Error specialist Fred Weinberg purchased the group. The California State Controller’s Office of Unclaimed Property later auctioned the collection.
Before the sale, the United States Secret Service inspected the collection and released it to the State of California, according to my original report. California then sold the coins, and the group dispersed into the marketplace.
That history matters because extraordinary Proof errors can raise obvious questions about how they left Mint custody. In this case, the Secret Service review gave collectors an important legal ownership history for that California group.
Gold Mint Errors Operate in a Different League
Few mint errors can match the visual impact of a familiar denomination appearing on gold.
Several famous pieces help put the Gold Washington Quarter into perspective.
A unique 1913 Type 2 Buffalo Nickel struck on a $5 Indian Half Eagle gold planchet sold for $400,000. That coin weighs 8.33 grams and represents another spectacular case in which dies for a base-metal denomination struck gold intended for a Half Eagle.
Then there is the extraordinary 1915 Panama-Pacific Half Dollar struck in gold. Only two examples are known. A PCGS Proof-64 example from the Bob R. Simpson Collection brought a record $750,000 at Heritage in 2022. Numismatic News reported that the Mint produced the clandestine pattern at Philadelphia on a cut-down Saint-Gaudens Double Eagle.
My original Gold Quarter article also discussed Indian Head Cents struck on $2.50 gold planchets. That article cited six pieces and placed their values at the time between $250,000 and $400,000. Other published Byers listings have cited five known examples, including three dated 1900, one dated 1905, and one dated 1906. Therefore, collectors should treat the six-piece figure as a period roster rather than a settled current census.
Likewise, my original article compared the Gold Quarter with the famous Sacagawea Dollar/State Quarter mule and cited more than 20 examples with then-current values ranging from $100,000 to $250,000. Published PCGS population estimates have varied over time. In 2022, PCGS described roughly 20 known and typical prices around $100,000 to $125,000.
Those changing numbers illustrate an important point. Error-coin populations can evolve as new pieces surface or researchers refine rosters.
The Gold Washington Quarter has not followed that pattern.
GreatCollections still presents the coin as believed unique.
From NGC PF66 to PCGS Proof-66
When Mint Error News first showcased this coin, NGC had authenticated and graded it PF66. It later appeared on the cover of Mint Error News Magazine Issue 66.
Today, PCGS grades the same remarkable error Proof-66. GreatCollections lists PCGS certification number 48183803.
The grade adds another dimension to the story.
A coin can survive more than half a century. A gold coin can survive an additional strike 72 years after its original manufacture. Yet this piece still retains Gem-level Proof quality.
When I first wrote about the coin, I noted how fresh its surfaces appeared despite the extraordinary circumstances of its creation. That remains one of its most striking characteristics.
1970-S Gold Washington Quarter Specifications
- Country: United States
- Date: 1970-S
- Denomination struck: Quarter Dollar
Mint Error: “Gold Washington Quarter” 1970-S Washington Quarter Overstruck on 1898 Gold Liberty Half Eagle - Mint: San Francisco
- Design: Washington Quarter
- Quarter designer: John Flanagan
- Host coin: 1898 Liberty Head Half Eagle ($5)
- Half Eagle designer: Christian Gobrecht
- Composition of host coin: 90% gold, 10% copper
- Error weight: 8.3 grams
- Standard 1898 Half Eagle weight: 8.36 grams
- Standard 1970-S Proof Quarter weight: 5.67 grams
- Standard 1970-S Proof Quarter composition: Copper-nickel clad over a pure copper core
- 1970-S Proof Quarter mintage: 2,632,810
- 1898 Philadelphia Half Eagle mintage: 633,420
- Current grade: PCGS Proof-66
- PCGS certification: 48183803
- Previous certification: NGC PF66
- Rarity: GreatCollections lists the coin as “Believed Unique”
- Auction: GreatCollections
- Closing date: Sunday, September 13, 2026, at 7:07:05 p.m. Pacific Time
A Quarter That Rewrites the Rules
Collectors often use the phrase “coin that should not exist.”
Few coins deserve it more.
For this piece to exist, a $5 Liberty Head gold coin from the McKinley era had to survive for 72 years. Somehow, that already struck coin then reached a San Francisco Proof press in 1970. Washington Quarter dies came down on it. The coin survived the process. It escaped destruction during quality control. Finally, it reached the numismatic marketplace.
Even more remarkably, enough of the original Half Eagle remains visible to prove what lies underneath.
That creates the real “wow” factor.
Look at the reverse closely and two moments in American coinage occupy the same piece of gold. One belongs to 1898. The other belongs to 1970.
GreatCollections will bring those two eras together once again when bidding closes on September 13.
By Mike Byers – Edited by CoinWeek
WOW! Is all I can say. But it was obviously done by a mint employee…
That is most definitely a WOW!!!! Thank you for the great article. I really enjoy everything on this site!
Another error what is going no. To many errors.
I would love to find any kind of mule error coin. The value could be life changing
That is an amazing coin and an amazing story.
OK, call me a conspiracy guy, but I believe someone at the mint is playing around and making this weird stuff. Great for collectors I guess, but “accident” or “mistake” or “somehow” are terms thrown around loosely. Shenanigans I say.
What is this quarter worth?
Interesting article. So many coins have so much of a story behind them.
NEVER even heard a whisper about this coin.
This is just an amazing story. I learn so much on CoinWeek.com
I want to win one of coins from your business
I want It!
interesting article. Thanks for the history lesson. (I wish I had the cash to bid on this item)
The origin seems fishy…
Little Mike’s somehow always near around or behind these once in a lifetime unique U.S. Mint errors that’s incredible I’m rubbing my hands in excitement for the next “Recently Surfaced Specimen” from legacy collections of Mint employees. I heard the Doubled Die Doubled Sided Double Doubler Buffalo Nickel struck on a Tripled Die 1908 D Gold Quarter Eagle is next. Whispers has it that a platinum Eisenhower Dollar quadruple die surfaces with Lyndon B. Johnson on reverse and Richard Nixon privy mark on obverse! Thanks for keeping it real Mike! Your the best!
What a mystery that will never be solved.
Fortuitous error.
Hard to believe this wasn’t an intentional act. Seems unrealistic that the gold coin just happened to get into the production line on it’s own after 72 years
Shenanigans at the mint
Wow! What a unique, one-of-a-kind coin! That’s one of the most expensive quarters to date!
I would love for somebody to start a research study of where most of the error coins are found in the United States. Because I always wonder if I’m just too far away and they never trickle down to my state, or if they’re scattered all over the US.
Very interesting !!
Someone at the mint had fun that day, that’s the only way I think would happen. What a cool coin! Thanks for the article.
Pretty cool
A lot of beating around the bush regarding “how it happened”. Obviously a mint worker brought in a gold coin, struck it, and smuggled it out. So many so-called “errors” of this type, I don’t really like them because they’re not actually errors. Just effectively some guy’s counterfeit to sell later.
I like the articles about US coins within my lifetime the most.
Wow
Amazing piece! Hard to believe it got past early inspections. But I don’t really know how they handle that. I would imagine with so many coins being struck, an error like this is possible, but also unique and one of a kind.
nice looking coin
Can’t wait to see what it brings.
Makes you wonder how this could possibly happen. Was it intentional?
Unique!
Perfection in imperfection.
I have studied coins all my life,,and this is the first that I had read or heard about this gold quarter, $5 Liberty Head gold coin; 1898…..stamped: pressed out to a 1970 quarter…..perhaps the greatest coin that was set to the proof collection status.
Just think, if it would have gone into the standard coin circulation??
Something like this just screams “inside job” to me rather than error. It seems that this was manufactured to bean unique coin. I don’t see how it could be an “error”
Cannot see the earlier date in the photo.
This is a magnificent error!!
That is very cool, but to me, reflects poorly on Quality Control
That’s awesome
That proof quarter is truly remarkable as I have never heard it existed till
Now. It will be interesting to see whst it brings gs at suction
omg. a coin from the 1800’s gets re-hit with a 1970 die, and no one knows how it happened???
Makes ya wonder if some so called errors were done on purpose??
Interesting story and a unique coin; quite a mystery.
What an awesome quarter
amazing
Sounds to me a mint employee was having some fun.
Fascinating article, first time I’ve read about this.
Wow such a rare error
midnight minter strikes again
Very Interesting ! Never Knew Such a Thing existed !
I’ve never seen a gold quarter.
This is a beautiful coin and one I would love to have to hold.
Someone brought in an 1898 $5 amd struck this. Total,BS,made,up,item…….
Inside job all the way
Amazing story. You can learn something new everday.
I agree with some of the other commenters who think this was purposely done by a mint employee. There is no way this was a legitimate “error”. However, it is definitely an interesting piece.
“Believed Unique” is an understatement for this piece. Wow!
A valuable mistake
This kind of mistake boggles the mind.
A real shame that the original coin had to be defaced for this error to exist.
amazing one-of-a-kind coin
curious about the value of this rare error
Out of my price range. Very nice though.
Bet it was intentional. Awesome coin though.
Special coin and it looks very nice
Quite a mystery.
So how much real gold is in this quarter or is it just on the surface from being struck by a gold coin?
It is 90% gold
This coin is definitely unique. So unique that it seems that there is something more than chance
Never knew about this
i can’t understand how these things keep happening. but they do.
Great coin to behold. Would love to own it. Having said the odds of this coin being an error as opposed to being done as the result of mint employee shenanigans is remote. My bet is on ‘shenanigans’ as the answer. Very happy to see it though.
Fascinating to learn about the 1970-S gold quarter error coin. Wish it was in my collection!
Love to have that in my possession!
What a crazy event. It was almost definitely done on purpose. I can’t see it being done accidentally. One of the reasons I like this hobby! Always a few crazy things like this going on throughout history!
90% Gold! Would love to find one of these to add to my collection someday.
I heard little Mike moved his shop to Fake City well he should feel very at home there oh it’s located on Fake Street just off Schmuks Ave. Across from Unique one of a kind used cars.
Someone thought it would be fun to create this single mule. And they were right
Interesting but how can something like this happen…