X-ray Microanalysis of Surface of the 286/287 AD Staters of Thothorses:New Data on the Silvering Process of the Bosporan Coins
The article deals with the results of XRF analysis of the composition of the alloy of the group of 286/287 AD silvered staters of the Bosporan king Thothorses from the Phanagorian 2011 hoard. For the first time, such elements as chlorine, calcium, sodium and magnesium were revealed on the surface of these coins that allows suggesting the use of the silvering paste composed of silver chloride. Other additives might be sodium chloride, ammonium chloride, potassium hydrogen tartrate, mercuric chloride and chalk as thickener. A similar technique of silvering of the surface of coins might be used in the Roman coinage from the late third to beginning of the fourth century AD.