X-Ray Technology Spotlights Fakes [Treasure Hunting, August 2009, Page 50, 51]
by Brett Hammond of TimeLine Originals
There is a very old joke about an inn-keeper who would proudly display to visitors a knife in his possession which had belonged to Oliver Cromwell. When questioned by a puzzled customer, the publican proudly stated “It’s had two new blades and three new handles – but it’s Cromwell’s knife just the same!”
Apart from reviving an ancient joke, my point here is to tackle the question of ‘genuine’ versus ‘fake’ items put up for sale. Anyone who has ever been bitten by the collecting bug will have had the experience of spotting that longed-for coin, buckle or what-have-you offered for sale. Maybe the piece looks or feels a little wrong, maybe it is unusually thick, or crudely-made, or simply in too perfect condition. Something about it just is not right – and then you face the dilemma of either buying it to fill the gap in your collection despite not trusting it to be genuine, or of declining it and living with the nagging doubt that it just might have been a genuine but unusual type.
Let us be quite clear: copies, reproductions and imitations have their place. Few of us would dare to handle a fragile Roman helmet if we were lucky enough to possess one, but a reproduction can be bought for a modest sum which can bring almost as much pleasure as owning an original, and without the heart-stopping terror of seeing it dropped or carelessly handled by visitors. The Romans themselves copied Greek statues and set them up in their temples, as a tribute to the civilization they greatly admired.
Copies are only a problem when they are forgeries – when they are misdescribed as genuine, and are fraudulently offered for sale as such.
As a dealer, the forgery problem is always at the back of my mind. I trade on my professional judgement, on spotting fakes and on being able to offer my customers a guarantee of authenticity even to the point where my business suffers for it. All the objects I sell are backed up by painstaking research by my team – the cost of which cannot normally be passed on through the purchase price.
The idea of scientific evaluation of antiquities is not new. Archaeologists have developed a range of techniques to establish relative dates for artefacts. One of the problems is that these techniques usually involve some form of damage to the item – scraping a portion of the surface off so that it can be heated up, or putting the item in a vacuum chamber. Few collectors are prepared to expose their valuable purchases to such treatment. However, there have been some recent developments in the fields of elemental analysis by X-ray coupled with increased efficiency of microprocessors which have led to the development of hand-held, portable devices which can analyse objects within minutes. These machines are used in the metal recycling, environmental and mining industries but they are now being exploited in the field of antiquities. Briefly, a machine which can analyse the constituents in an object’s surface can supply a record of which elements are present and in which proportions. These results can be compared with the results from known genuine artefacts and obvious modern copies can be spotted immediately.
X-ray fluorescence (XRF) is non-destructive and safe. The machine uses x-rays to create a minute area of fluorescence on the surface, which it then analyses. The penetration of the x-rays is at the sub-atomic level so that there is no visible sign of the process – even the surface patination is untouched by this method. This has obvious advantages where rare, fragile or high-value pieces are involved.
The priceless expertise of companies such as Oxford X-ray Fluorescence (see details below) lies in being able to compare the results of any analysis with a database of known genuine cases. As well as spotting deliberate modern fakes, this technique can also identify mis-described ‘tourist pieces’ – copies of genuine artefacts made for sale at tourist destinations. Anyone who has visited the Coliseum or Pompeii, to name just two obvious examples, will have seen the array of ‘bronze antiquities’ on sale from street-vendors. These items are not ‘fakes’ because they are sold purely as souvenirs for a few Euros without any suggestion that they are ancient. Most are so obviously modern (some are even made from resin!) that no buyer could possibly believe them to be old. But some of the more expensive pieces are well-made and given a superficial patination; on their return, the tourists often pass such items on to relatives, or charity shops and other markets, and along the way they are magically transformed from ‘modern tourist’s souvenir’ into ‘ancient Roman artefact’.
There is of course a third position between ‘genuine’ and ‘fake’, which is ‘undetermined’. Many detectorists will have had the experience of finding a group of, say, Roman small finds on a site which they are legally searching, among which is a gold ring or piece of jewellery. This is dutifully reported to the authorities, and is then returned with a statement of ‘date undetermined’. As an item of unknown date, the ring is of limited value but if it can be shown that it is of Roman provenance its value increases immensely, especially if its associated objects are all dated to the same period. XRF testing can help here, and the possibilities for proving (and disproving) associations between objects found on the same spot are obviously very important.
I hope that the use of techniques such as XRF will become common among antiquities dealers - and will be supported as much by collectors as by dealers. For a small investment of money and time, almost any artefact can be analysed. The greater the spread of XRF results through the coin and antiquities trades, the greater will be the confidence with which both dealers and collectors can buy and sell. Reliance on experience will never be replaced, but it can and should be backed up with facts and figures wherever possible.
TimeLine Originals have used the XRF antiquities testing service for some time with very promising results and certification. Now try this service for yourself. The website of Oxford X-ray Fluorescence Ltd can be found at http://oxford-labs.com where details of the process and costs are explained. They can be contacted by email firstname.lastname@example.org.
By Brett Hammond of TimeLine Originals
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