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Posts Tagged ‘Error’

Have I found a rare coin? £2 ‘errors’ explained!

So you’ve noticed something’s not quite right with the £2 coin you’ve just found in your change. A quick google search of the strange variation you’ve noticed brings up a plethora of eBay listings and news articles claiming that you’ve just hit the jackpot and your ‘error’ coin is worth a small fortune!

Sadly, in this instance Google is not your friend and whilst genuine errors are out there, so too are a number of common mis-strikes and myths, or even fakes that have been manipulated to look like an error.

So what is the difference between a mis-strike and an error I hear you ask.

Put simply, a true error is caused by human mistake, such as the wrong die or metal being used to strike a coin, whereas a mis-strike is created by the mass production process, as hundreds of thousands of coins are struck, meaning variations are bound to occur, especially when dies and machinery become worn.

But which mis-strikes on the bi-metallic £2 coin should you be aware of?

I recently read Scott Wren’s article, ‘Bi-metallic “errors”… Why two is better than one’ published in Coin News which highlights some of the mis-strikes found on £2 coins and how their bi-metallic quality causes the differences to be something entirely more spectacular than those found on monometallic (single metal) coins.

Striking bi-metallic coins

In order to understand why mis-strikes on bi-metallic coins are often more pronounced than monometallic coins, it’s first a good idea to look into how these coins are produced.

When striking £2 coins, the first step is to punch a hole through a blank planchet to create the outer section. The inner core is taken from a different metal, sized to fit inside the outer ring.

Have I found a rare coin? £2 'errors' explained!
Groove milled around the inner core of a £2 core

A groove is milled around the edge of the inner core so that when both parts are struck together, the metals will fuse as the outer ring deforms and spread into the groove, locking it into place.

Now that we know how £2 coins are struck, here are some of the mis-strikes and errors that can occur in the process…

The following images of variations found on £2 coins have been taken from Coin News for use in this blog.

Clipped Planchet

Have I found a rare coin? £2 'errors' explained!

Figure 1 shows how the inner core was punched out from the end of the sheet of metal used for blanks, forming a straight or ragged edge clip.

Whilst this also occurs with monometallic coins, the pairing with an outer ring exposes a large gap which is much more noticeable.

The Royal Mint strike millions of coins each year so it is inevitable that variances will occur during the striking process and can’t always be picked up during quality control, despite the fact that this particular coin would weigh less than the standard 12g £2 coin. However, a small quantity of coins do sometimes manage to slip through the net and as i’m sure you’ll agree, they make for interesting collecting.

But before you pay over the odds for one of these coins, beware of fakers! Some coins are manipulated to look like mis-strikes or error coins and sold to unsuspecting buyers. Check the clipped planchet edge of the coin to see if it’s genuine by making sure the detail of the design fades away towards the edge rather than suddenly stopping, which would indicate the coin had been cut.

Off Centre Inner Core

Have I found a rare coin? £2 'errors' explained!

Figure 2 shows an inner core which hasn’t been united properly prior to being struck.

Due to the way the inner and outer core are struck together with the two metals being lined up and then fused together during striking, a misalignment will mean that the inner core spills into the outer ring, as seen in the image above. There might also be a gap between the two metals on the opposing join.

This mis-strike is thought to be fairly common on the bi-metallic 12 sided £1 coin as well as some of the Technology £2 coins and even foreign bimetallic coins, but have you ever spotted one in your change?

Faulty Outer Ring

Have I found a rare coin? £2 'errors' explained!

Figure 3 shows a faulty planchet or outer ring, where the inner core is exposed.

In the image above, you can actually see the specific engineering design features where the inner core is grooved to help the metal flow bond to the outer ring and fuse during striking.

Similar to the first mis-strike we looked at, this could be caused by a clipped planchet, this time created when the outer ring was punched, however coins like this may also be caused by tampering post striking, for example by fakers trying to replace the inner core of a £2 with another coin to pass off as a rare error.

The Holy Grail of Bi-metallic ‘Errors’

Have I found a rare coin? £2 'errors' explained!

Figure 4 is described as the Holy Grail of bimetallic ‘errors’ and is the result of the nickel-brass £2 blank not having the inner core section punched out before being struck.

This means that the £2 coin is made from one full piece of nickel-brass, completely contrasting the very idea of a bimetallic coin.

A 2007 monometallic £2 was verified by The Royal Mint and in the email confirming the mis-strike it was mentioned that they had only seen 4-5 similar coins before.

This rare striking error is highly sought after and coins have achieved extraordinary prices in private sales and auctions.

Foreign Planchet

Have I found a rare coin? £2 'errors' explained!

Finally, figure 5 shows a £2 design struck on the wrong planchet – a blank normally used to strike a different coin.

As The Royal Mint strikes a huge quantity of coins for different denominations and even different countries, blanks can sometimes end up in the wrong striking chamber, creating a wrong or foreign planchet error.

This is actually down to human error rather than a mis-strike and the coins would normally be picked out during quality control, however some have been spotted in circulation, not only on the £2 coin, but on various different denominations across UK coins and world wide.

One of the most famous examples in the UK is the silver 2p a 2p coin struck on to a 10p blank which sold for 67,580 times its face value at auction.

So how much is my ‘error’ coin worth?

These mis-strikes and errors certainly make for interesting collecting and the rarer variations, such as monometallic £2 coins could certainly sell for over face value.

In fact, one such monometallic mis-strike found on a 2007 Technology £2 is estimated to be worth over £1,000!

Ultimately, as with all coins, it’s all down to how much an individual collector is willing to pay to add that coin to their collection.

If you’ve found a £2 coin with a mis-strike, it’s certainly worth having it verified and authenticated by The Royal Mint, who will supply a letter detailing their findings.

So have you found any interesting variations on your bimetallic £2 coins? Let us know in the comments below!

With thanks to Scott Wren from Coin News.


If you’re interested in coin collecting, our Change Checker web app is completely free to use and allows users to:

– Find and identify the coins in their pocket
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– Swap their spare coins with other Change Checkers

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Is this a new £1 minting ‘error’?!

Last year we reported on the ‘Dual-dated £1 coin error’ where the dates on the obverse and reverse were different, one reading 2016 and the other 2017.

Now another £1 coin ‘error’ has been discovered and this one is very interesting indeed! It would appear that a 12-sided £1 coin die has been struck on an old round £1 coin blank.

Is this a new £1 minting 'error'?!

The latest £1 ‘error’ coin appears to be a 12-sided £1 die struck on an old round £1 coin base. (Image: Zeki Atma)

In the past week alone, we’ve seen 3 examples of this ‘error’ coin.

The first was from a Change Checker from Burnham-on-Sea who told us that they’d listed the coin on eBay. After receiving 22 bids, the coin sold for £205! 

Is this a new £1 minting 'error'?!

One of the first examples of this ‘error’ coin has sold for £205 on eBay!

Another coin is being sold at an auction in London on Wednesday 21st February. The auctioneers, ‘Timeline’, who are based in Berkeley Square, describe the coin as an “exceptional modern rarity” and go on to say “…the coin is sure to attract much attention when it crosses the block later this year”.

Is this a new £1 minting 'error'?!

Another example of this latest ‘error’ will be available to purchase at auction on the 21st February. (Image: Coin news)

The third report we have received was this morning from another Change Checker. Our advice to anybody who believes they have found this coin, or any other ‘error’ coins, would be to send the coin off to The Royal Mint Museum who offer a free verification service.

They will send the coin back to you with confirmation of their findings, which can take a few weeks depending on demand for the service. Here is the address:

Dr Kevin Clancy, Director of the Museum, The Royal Mint Museum, Llantrisant, Pontyclun, CF72 8YT

As yet, we have not seen proof that these coins have been verified by The Mint, so whilst they look genuine we will keep an open mind for the time being.

As usual, if you think you have found one of these coins or any other interesting ‘errors’, we’d love to hear from you.

The truly unique ‘Bronze 20p’ error coin

ENTRIES TO THE ‘BRONZE 20P’ DRAW ARE NOW CLOSED

We love to hear when Change Checkers make a great coin discovery. We’re often contacted about mis-strikes which are interesting oddities but what really excites us are ‘error’ coins.

Genuine ‘error’ coins, especially those verified by The Royal Mint, are VERY rare and finding one is a goal for many change collectors.

So imagine our excitement when somebody contacted us after finding one of the rarest ‘error’ coins yet!

The ‘Bronze 20p’

Earlier this year, we were contacted by a collector named David Crosier who informed us he’d found a very rare ‘error’ coin.

A collector for over 50 years, David told us how he’d often look out for mis-strikes and ‘mules’ but there was something special about this particular coin. Initially he presumed the coin was plated but decided to send it to The Royal Mint to be certain.

The truly unique ‘Bronze 20p’ error coin

The ‘Bronze 20p’ flanked by a 20p and 1p coin from the same year

After examination by x-ray fluorescence spectrometry, the coin was confirmed by The Royal Mint as an extremely sought-after minting ‘error’.

Somehow a 1p ‘blank’ found its way into the presses and a 20p was accidentally struck onto it.

The truly unique ‘Bronze 20p’ error coin

The ‘Bronze 20p’ is significantly thinner than he standard 20p coin

Errors like this are extremely rare, in fact so rare we’ve never heard of another ‘Bronze 20p’, but The Royal Mint verified the authenticity of the coin with a letter and so here at Change Checker we knew this was an opportunity not to be missed.

The truly unique ‘Bronze 20p’ error coin

Chris Barker, Assistant Curator for The Royal Mint Museum, confirmed the ‘Bronze 20p’ as a genuine ‘error’ coin

Now the great news… we want to give away the amazing ‘Bronze 20p’ to one lucky Change Checker!

And what’s more, you won’t just win the ‘Bronze 20p’, the coin is set in a specially designed presentation box alongside a Brilliant Uncirculated 1p and a Brilliant Uncirculated 20p coin from the same year, beautifully highlighting the minting error.

The truly unique ‘Bronze 20p’ error coin

The ‘Bronze 20p’ is housed in a specially designed presentation box alongside a Brilliant Uncirculated 20p and 1p coin from the same year.

Your chance to win the coin

We’ll be selecting a lucky Change Checker to win this coin.  If you’re already registered then we’ll automatically include you in the draw.

To register your free account, all you need to do is enter your email address and choose a password.

ENTRIES FOR THE ‘BRONZE 20P’ DRAW ARE NOW CLOSED

Full Terms and Conditions can be found below.

Good luck!


Terms & Conditions

  1. All registered members of changechecker.org at midnight on 7th December 2017 will be automatically entered into the prize draw. No purchase is necessary to register.
  2. The draw will take place on 11th December 2017 and the winner will be notified on that day by email to their registered changechecker.org email address.
  3. The winner will receive the “Bronze 20p”. There is no cash alternative.
  4. Participants agree to meet reasonable requests to assist publicity.
  5. The prize draw is promoted by The Westminster Collection / Change Checker, trading divisions of 288 Group Ltd.
  6. Employees of 288 Group and their families are not eligible to enter.