Can scientists determine where the metal in an ancient coin was mined?

Discussion in 'Ancient Coins' started by Gam3rBlake, Feb 22, 2022.

  1. Gam3rBlake

    Gam3rBlake Well-Known Member

    Does anyone happen to know if it’s possible for scientists to determine where the copper/silver/gold in a coin was mined? Or at least an approximate location?

    It would be so cool if a tiny (unnoticeable to the eye) bit of metal from a coin could be analyzed and a specific origin could be determined of exactly where the metal was mined.

    I imagine for some coins like the Athenian tetradrachm it wouldn’t really matter since the vast majority of silver came from the Mines of Laurion.

    But for Ancient Roman coins it would be awesome to see where in the Empire a coin’s metal was originally mined.
     
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  3. robinjojo

    robinjojo Well-Known Member

    I know that studies have been done on the silver from Laurium, Greece. There is a very lengthy, technical research article online.

    https://www.sciencedirect.com/science/article/pii/S0305440319301542

    In the case of the owls produced in Egypt at the close of the 5th century and the beginning of the 4th century BC, analysis of the silver used to make these coins indicate that Laurium was the source, possibly as silver exported to Egypt from Athens or another Greek source. Some scholars think the initial dies also came from Athens, and copied over the subsequent decades.
     
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  4. JayAg47

    JayAg47 Well-Known Member

    Another way to look at it, knowing the metal composition can help create 'fingerprint' database for certain coins. For instance Caesar's gold aureus minted in Gaul came from the gold coins of the captured tribes, different in composition from the issues from Rome. Similarly we could authenticate a rare ancient coin, something like an Eid Mar denarius/aureus or a dekadrachm based on its composition to see if it matches with a contemporary coin, given modern forgeries may use pure gold or silver to make fakes.
     
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  5. Al Kowsky

    Al Kowsky Well-Known Member

    Blake, I think the link below will be helpful ;).
    Microsoft Word - art03Constantinescu.doc (academiaromana.ro)
     
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  6. medoraman

    medoraman Supporter! Supporter

    All good answers. From what I have read over the years, not so easy to prove a specific mine unless its something like the Laurion mines of Athens, but we certainly look at metal composition. We actually study the imperfections in the metal, what are they and at what levels, to compare coins. This is one of the reason the "Black Sea Hoard" was so deceiving, they actually melted down ancient silver coins, (hopefully defectove or worn out ones) and restruck them on fake dies. However, by reusing ancient silver, metallurgy could not disprove the coins.
     
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  7. -jeffB

    -jeffB Greshams LEO Supporter

  8. Victor_Clark

    Victor_Clark all my best friends are dead Romans Dealer

    There is a series of mine coins

    info and pic from CNG--

    Under Trajan and Hadrian several series of bronze quadrantes were struck in the names of the imperial mines in Noricum, Dalmatia, Pannonia and Moesia (Dardania). These operations supplied metal for the mint at Rome

    411421.jpg

    Hadrian. AD 117-138. Æ Quadrans (15mm, 2.43 g). Dardanian mines issue. Helmeted and draped bust of Roma right / DARDA-NICI, Woman standing left, holding grain ears and lifting hem of skirt. RIC II 1016 (Hadrian)
     
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  9. ancient coin hunter

    ancient coin hunter 3rd Century Usurper

    Very interesting Victor.
     
  10. Insider

    Insider Talent on loan from...

    AFAIK, some of the guys collecting colonial Mexican 8R have done it.
     
  11. medoraman

    medoraman Supporter! Supporter

    Yeah, but I would be leery of such results. The very act of coinage surface enriches certain metals, a fact the Romans used to silver coat their late bronzes, would skew the results tremendously. In short, surface analysis will never give you a true metal composition of the entire coin. Its a datapoint, but one that should always be viewed with this major limitation known.
     
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  12. -jeffB

    -jeffB Greshams LEO Supporter

    You're right, of course. And reading further into the article, I see that some of their analyses did require removing small amounts of material (a few milligrams) from the objects.

    Neutron activation could give composition throughout the piece, I believe, but the Romanian authorities didn't allow them to do that. It's technically not non-destructive, as a tiny fraction of the material gets transmuted into other elements, and the object can remain radioactive for quite a while afterward, but hey, besides that... :rolleyes:
     
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  13. Silphium Addict

    Silphium Addict Well-Known Member

    The chemical composition of silver in coins can be traced to certain deposits based on isotope analysis and metal ratios. For example, silver analysis of Roman coinage around the time of the Second Punic War confirms the historical context:

    The quadrigatus of higher silver content struck before and early in the war used silver from Spain, undoubtedly from the large silver indemnity Carthage paid Rome after the First Punic War. The silver composition of the denarius when it was introduced is different, probably reflecting the large amount of silver obtained from the sack of Syracuse 212 BC. Later denarii reverted to Spanish silver after the capture of Carthago Nova by Scipio 209 BC.

    Here are a few references:
    A general article on silver analysis:
    J.a. Milot, C. Malod-Dognin, J. Blichert-Toft, et al., "Sampling and combined Pb and Ag isotopic analysis of ancient silver coins and ores," Chemical Geology (2020)
    https://www.researchgate.net/public...pic_analysis_of_ancient_silver_coins_and_ores

    F. Albarède, J. Blichert-Toft, M. Rivoal, and P. Telouk, ‘A glimpse into the Roman finances of the Second Punic Was through silver isotopes", Geochemical Perspective Letters 2 (2016), pp. 127-37
    https://www.geochemicalperspectivesletters.org/article1613
    Summary at:
    https://www.sciencedaily.com/releases/2017/08/170814092835.htm

    Jean Milot et al, "Silver isotope and volatile trace element systematics in galena samples from the Iberian Peninsula and the quest for silver sources of Roman coinage", Geology (2021).
    Summary at:
    https://phys.org/news/2021-12-sources-roman-silver-coinage-iberian.html

    Here's an early quadrigatus: jt046.jpg
    Rome Anonymous 225-212 BC
    AR quadrigatus 6.6 gm
    O: laureate head Janus
    R: Victory and Jupiter in racing quadriga right; Incuse ROMA below
    RRC 28/3
     

    Attached Files:

  14. Jay GT4

    Jay GT4 Well-Known Member

  15. Curtis

    Curtis Well-Known Member

    Speaking of destructive v. non-destructive:

    While there is a lot that can be done with non-destructive analysis, and more all the time, I've been happy to pick up a few of the (wonderful) scraps from the destructive analysis. Both of the coins below are from Butcher and Ponting's (2014) book, Metallurgy of Roman Silver Coinage, from the Reform of Nero to the Reforms of Trajan -- as well as a number of associated articles. And previously Jyrki Muona's collection (and one also Orfew's).

    Mostly for the metallurgy they just needed to drill holes. But, at the expense of several dozen Roman denarii and other silver coins, they found that many of the long-held beliefs about the composition of Roman silver coins were grossly mistaken -- namely, the findings of Walker's studies, 1976-1978. After 40 years of being mistaken, they were able to provide a corrective. Importantly, the surface of the coins is often very different from the core (sometimes, I recall, because of what's happened to the coins from 1900 years in the soil, sometimes due to enrichment of the surfaces at the time of striking).

    The two coins below were important because the cross-sections allowed one to see exactly how the alloys varied between core and surface, and how they may have changed over time. Both of these coins were ex-Jyrki Muona Collection, later among 65 similar denarii sold by Berk, some of which were dispersed to other dealers.

    The Titus (M40) was previously @Orfew 's (I was delighted to get it in the group lot, and if you're seeing this, yes I did track down all the provenance info from your posts that CNG left out, so it's not lost!). The Otho (M16) I bought from HJB BBS 215.

    The second two photos are the "Before" photos from the Archaeology Data Service (UK) website, where Butcher & Ponting's dataset is housed: https://archaeologydataservice.ac.uk/archives/view/coins_lt_2005/

    (Credit: I believe the cut Titus photo is the one @Orfew used here on CT when he shared the coin -- I hope that's okay! Or perhaps Marc Breitsprecher's in between HJB and Orfew.)
    Titus Denarius Muona, Butcher, HJB, Breitsprecher (photo), Short, Triton XXV.jpg Otho Denarius (Ex Muona M16) HJB BBS 215 153.jpg Otho Denarius Ex Jyrki Muona Cambridge Database.jpg Titus M40 Muona Orfew Denarius 'Before'.jpg
     
    Last edited: Feb 23, 2022
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  16. Orfew

    Orfew Draco dormiens nunquam titillandus

    Curtis,
    In the last little while, I have heard from a few that now own my coins from the CNG sales. I cannot tell you how happy I am that you now own this coin. It deserves to be in the collection of one who truly appreciates it for what is it-an important coin. If anyone reading this has won a coin of mine please let me know.

    I am thrilled that the provenance has been preserved. I feel that this is a not only protection against the coming more restrictive laws concerning the ownership of ancient coins, but it is a vital part of the coin's stories. I am sure that each of our coins tells multiple stories. I am glad you now know a few more about this Titus.

    Curtis, thanks again for reaching out.
     
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  17. Gam3rBlake

    Gam3rBlake Well-Known Member

    Yup that is true! I only knew that because I looked up the history of my own Quadrigatus xD.

    576BE3B9-C1D4-41E8-B2A7-D5385422ECA2.jpeg


    You’ll notice the oldest Quadrigatii were made of a much purer than the ones minted after Hannibal started rampaging through Italy.
     
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  18. robinjojo

    robinjojo Well-Known Member

    As a side note, during the Mexican Revolution, 1910-1920, the revolutionary force under Emilio Zapata struck one and two pesos coins in the state of Guerrero. Unable to refine the ore used to produce these coins, and since that ore had a high gold content, that content, 0,595, is noted on the coin's reverse, above the sun over mountains. These coins were produced in make-shift mints from 1914-1915.

    D-Camera Mexico Guerrero dos pesos 1914 zapatista Oro-0,595 km 643 2-26-22.jpg
     
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