Ancient Copies

Ancient Copies, also known as fourrées, ancient counterfeits, and plated coins are defined by David Sear as "a plated counterfeit coin with base metal core, usually in imitation of a silver denomination, though occasionally of gold. This normally indicates an unofficial product, though some fourrée appear to have been produced from official dies at the mint". There is much debate over whether these coins were done by the government to save on silver, corrupter celators minting the coins, or other thieves. For an excellent discussion of ancient copies, please check this link.

An ancient copy is made from a base metal usually copper flan that is struck with dies and then coated, plated or by some other means (see above links for the ways this was done) was made to look like a silver or gold copy of the coin. Here is a base metal coin of RSC 39a that all the silver has been worn off:

The key to spotting the ancient copy can be looking for base metal below as in the following examples:

So what does an ancient copy look like without the base metal so easily exposed? Here is one:

So if there isn't a telltale sign of base metal what can you look at. First check the style of the coin. This coin has a very rough style. It looks much more like a coin from the mint of Antioch then Rome. Checking my page on Mints and my Quick Info Page, you can see that this couldn't be a coin from Antioch because PMTRPIII isn't listed as a coin from the Antioch Mint and the date of PMTRPIII is past the date of last known coins from this mint. Next check the coin references. Many references will also have listing for ancient copies as (base, plated, or AE) after known imperial mint examples. Next look at the weight. This coin had a weight of 2.56 grams, very light for an imperial example. You can also check the color. The dull gray instead of silver color gives this coin away also. Lastly, you can have the coin have a nondestructive metallurgical test to determine the metal content of the coin. High copper content and lower than typical silver content will be an obvious give away. The above coin was sent for metallurgical examination and did come back as high copper and more debased (less silver) than other known imperial coins of the same time. The official report on it was:

The coin with the reverse legend: PM TR P III COS PP is 18.5-19.2mm in diameter, weighs 2.56 grams and has a die axis of 6 o'clock. The portrait style is somewhat crude and the planchet appears to be crystallized slightly. Analysis of the metal determined it to be heavily debased to a degree more consistent with the later issues of Valerian than those of Severus Alexander (17-25% silver versus 50% for a typical Severus Alex.). The planchet contains copper and silver, minor arsenic and only traces of gold, lead, and bismuth. Lead is in my experience always present in official issues of debased Roman silver. Taken in concert with the high level of debasement, I am strongly inclined to suggest the coin is a contemporary, unofficial copy of a denarius rather than the product of an Imperial mint. (One obvious motive for issuing it is profit in the manner of a fouree.) A quick glance at RIC vol.4 revealed other coins of the style of the Antioch mint in base silver .