10 years ago: counterfeit coins


© Shutterstock

Recently I discovered a £1 coin which was slightly more golden than others, and a more detailed examination showed a minting date of 1990 and a Scottish reverse. A report of these facts to the Royal Mint confirmed that this was a counterfeit coin. Despite the above information, and certain other minute details, this was clearly a match for a true £1 coin and had escaped the attention of previous recipients. Having sent the coin to the Mint, I have now been informed that x-ray fluorescence (XRF) spectrometry showed it to be made of leaded brass rather than the usual alloy.

Letter from J D R Thomas in Chemistry World (February 2004)

 

Ed. Recent surveys have shown that as many as 3% of all UK £1 coins are indeed counterfeit, though the number has fallen slightly in the last year or so.As a result, there have been several calls for the Royal Mint to scrap the entire denomination and reissue it. Genuine £1 coins consist of an alloy of approximately 70% copper, 5.5% nickel and 24.5% zinc. XRF analysis remains the favoured technique for the analysis of coins both ancient and modern.


Related Content

Coin isotopes unravel ancient inflation riddle

24 May 2011 News Archive

news image

Isotope analysis of silver coins sheds important light on economic inflation in Europe in the 16th and 17th centuries

Chemistry World podcast - December 2013

3 December 2013 Podcast | Monthly

news image

We discover how spin chemistry guides migrating birds and explore the science of cheese

Most Read

Hydrogel with a basic instinct for drug delivery

15 April 2015 Research

news image

Gel that releases naproxen in alkaline surroundings is promising step toward relieving drug’s side effects

Early Earth collision could clear up two geological mysteries

16 April 2015 Research

news image

Smash-up with Mercury-like body could have ignited nuclear dynamo at Earth's centre and explain isotope discrepancy

Most Commented

Membrane-less electrolyser set to disrupt water splitting

20 April 2015 Research

news image

Device that exploits fluid mechanic forces has potential to significantly cut cost of hydrogen production

Oh, the humanities!

20 April 2015 The Crucible

news image

Science and the arts are equally essential to society, says Philip Ball. Don’t divide them by their differences