Discovering sources of Roman silver coinage from the Iberian Peninsula

Interesting article:

"Despite its prior status as a luxury commodity, silver became widely used for coinage in the Roman world from the 7th century BCE onward and provided a standardized monetary system for ancient Mediterranean civilizations. However, the sources of silver used to produce Roman coinage have largely been used up, making it difficult to determine which deposits Roman miners exploited.

"A new study published in the journal Geology yesterday evaluated silver sources from different mining provinces in the Iberian Peninsula to determine which locations may have been mined for silver to produce Roman coinage.

"'The control of silver sources was a major geopolitical issue, and the identification of Roman silver sources may help archaeologists to reconstruct ancient fluxes of precious metals and to answer important historical questions,' said Jean Milot, the lead author of this study.

"The Iberian Peninsula, which includes modern Spain and Portugal, is host to world-class silver deposits, especially in the southern region. These deposits contain galena, which is the main ore of lead and an important source of silver. To extract silver, the galena ore is smelted and purified, with refined silver for coin minting able to reach a purity of over 95%.

"To track the source of Roman silver, the team of researchers analyzed the silver and lead compositions of galena samples from ore deposits across the Iberian Peninsula and compared the results to the chemical signatures of silver Roman coins.

"They identified two different types of galena deposits based on the silver elemental composition of the samples: silver-rich galena that would have been a likely source for Roman coinage, and silver-poor galena that would have been exploited for lead only and would have been of lower economic importance.

"However, few of the ore samples had a composition that fit the silver elemental composition of the Roman silver coins. Silver-bearing ores spanned a wide range in compositional variability, but Roman coins notably have a very narrow elemental composition range.

"Based on the lead elemental signatures of the galena samples, the ore deposits from southeastern Spain best fit the composition of Roman coins, suggesting that these deposits were a major source of Roman silver. Both silver-rich and silver-poor galena deposits were likely exploited here, with the extracted lead from silver-poor galena able to be mixed with other ores to extract silver"

M. Herennius, 108-107 BC.
Roman AR Denarius, 3.41 g, 17.4 mm, 3 h.
Rome, 108-107 BC.
Obv: PIETAS, diademed head of Pietas right.
Rev: M • HERENNI, Aeneas carrying his father Anchises, r.; Control-mark L• in lower right field.
Refs: Crawford RRC 308/1b; Sydenham CRR 567a; RSC I Herennia 1a; RCV 185; BMCRR 1272.​

 

Log in or Sign up to hide this ad.

That's interesting info, @Roman Collector. Thanks for sharing. I wonder if the silver mine that Athens relied on for its tetradrachm was already exhausted during Roman times.

 

According to Wikipedia article on the Mines of Laurion:

"After the Peloponnesian War had ended and the mines had run dry, this devaluation and re-minting of Athenian coins was brought to an extreme all over Attica. The ruler known as Dionysios I of Syracuse ruled from 405-367 BC ordered that all the coinage be collected and re-minted at double its original value.[22] If citizens refused to do so they were threatened with death sentences.[22] Another ruler known as Leukon I of the Cimmerian Bosphoros who ruled from 389–348 BC imposed almost the same thing but did not threaten the punishment of death.[22] Instead, he decreed that all coins that remain the same will be essentially worthless.[22] As leaders across Attica devalued their silver, the Laurion mines became active again around 370 BC, when some businessmen decided to rent out some of these recently abandoned mines.[23] They were more successful than expected resulting in a small economic boom in the greater Laurion region in 340 BC.[23] However, the mines were outcompeted by the rising gold and silver industries in Macedonia and Thrace.[23] Silver prices plummeted when Alexander the Great finally obtained the Persian silver industry.[23] However, the Romans defeated the Macedonians in 168 BC and later ordered the shut down of all of their mines to prevent Macedonia from rising again. This opened up an economic opportunity for Athens to seize. The Romans provided cheap slave labor and new technologies gave the Greeks new means of extracting silver in more efficient ways.[23] The Laurion mines were revived for a short while but they would never become the silver river they had once been."

 

Curious. The Roman Republic relied on Bronze (AES), until the Second Punic War when Rome wrested the Iberian mines from Carthage and the Barcid Family.

Does this mean that this same Galena Silver signature is reflected in Carthage Empire silver, and should actually be referred to as the Barcid or Carthage Silver signature?


Carthage Zeugitania
AR ½ Shekel
17mm 3.8g
2nd Punic War 218-202 BCE
Sicily mint 216-211 BCE
Tanit l
Horse r sun as double uraeus
SNG COP 359

 

Interesting idea! You inspired me to write to the authors of this paper and suggested they do a metallurgic analysis of Carthaginian coins of the period.