Electrum is defined as having at least 20% gold and 20% silver (weight) present. The electrum coinage of Mytilene minted between 477-326 BC, had an average gold content of 42% with a +/- 14% variable in specimens examined. Cited from German Numistatist, Friedrich Bodenstedt's study. In which he analyzed the metallic content of over 50 electrum coins minted in that era. (see chart below. group 2-9 represents coins minted from 477-326 BC.) The coins I have acquired fall within groups 2-5 (Winged lion, minted between 412-378 BC. ) and groups 6-9, (3/4 facing Athena, minted between 377-326 BC.) The latter showing tighter percentage groups. As you can see from the coins below, there is an obvious difference in metal color; but according to the study, the percentage of gold would nearly be the same. Outside of numismatics (and maybe this study. ) one would assume the 3/4 facing Athena would have a much higher gold content due to a deeper gold color, ergo the Winged lion having less of a gold content and maybe more silver due to lighter saturation. Although this would have some effect on color; the main is due to presence of copper. Bodenstedt states the main reason for inconsistencies in color amongst examples with fairly close gold and silver content is the amount of copper present. Copper, iron, bismuth, palladium and (very rarely) platinum occur naturally in electrum. Copper has more effect on color than any other metal present due to its natural darkness and the way it chemically alloys with other metals (chemistry that is beyond my knowledge.) It should be safe to assume that my 3/4 facing Athena would have a slightly larger copper content; maybe in the range of 2-5%. Amazing what a little metal is capable of. In any metallic event, it still amazes me what the engravers could with a 12 mm flan. Without the presence of die rust on the Winged lion, the lines would be incredible. 412-378 BC, Hecte, Bodenstedt-63. Forepart of winged lion left / Sphinx seated right, in linear square. 2.57g 11.3mm 377-326 BC, Hecte, Bodenstedt-86. Head of Athena facing, wearing triple-crested Attic helmet /Draped bust of Hermes right, his petasos hanging behind his neck, in linear square. 2.50g 11.9mm The symbolism on all devices are apparent aside from the winged lion; but, if biblical creatures from the book of Daniel and Revelations lend any credence... Maybe a winged lion represents the speed at which they inflict destruction? Post 'em. -Michael
Nice!! ... those are two beauties, iamtiberius (congrats) Oh, and thanks for the info ... Yah, I have one example (I wish I had more!!) LESBOS, Mytilene. EL Hekte – Sixth Stater Circa 478-455 BC Diameter: 10 mm Weight: 2.48 grams Obverse: Ram’s head right Reverse: Incuse bull’s head right Reference: Bodenstedt Em. 27; HGC 6, 954
Interesting info. Unfortunately I do not have any Greek electrum to contribute, I can appreciate the science behind the study, neato. Curious why is the margin of error so large +/- 14% ?, yikes.
Love the bull incuse. At the rate in which these are popping up in every major auction and the fact that they're usually covered in fauna, I see more in your future.
Beautiful pieces, and the metallurgy of coins is always fascinating to me. I have yet to collect any of these, but someday...
Lovely coins!!! I regret I have none of these types to post...and I'm as amazed as anyone what the ancient engravers could accomplish on such small or even smaller coins----The 'electrum' alloy mixture allows such a gorgeous toning.....
Group 3 is the one that threw in 1 example with a 47%; that being the exception, the rest stayed at 43% and below. I honestly do not know the reasoning, though. I would imagine Bordenstedt explains somewhere in his book, but it was hard to copy and paste his writing in google translate and try to make out exactly what he was saying. I would imagine they either used the alloy as found from the ground, after refining; or depending on the mint, added metals to alloy at their discretion.
Was the Island of Lesbos an area in which electrum occurred naturally, as in Lydia? If so, they may have done little with the alloy other than melt it down and shape it into flans...
I'm leaning toward this. Metal changes a lot the deeper you go into a mine; let alone a different location all together. With the lack of chemical analysis, maybe the issuing supremacy and citizens just accepted the composition for what it was and let their electrum coinage be guided purely by weight.
I would like to see you or steve and anyone with an old Greek electrum coin, determine the Specific Gravity. Although this method is not full proof the margin of error can be mitigated, especially if a medium is heavier than water. (The lighter the medium, the greater the error will be, but the heavier the medium the calculation only becomes slightly less intuitive.
those are beautiful, man....i wish i had one to post. interesting on the chemical analysis. that led me to the wikipedia page on electrum, which mentioned the greeks used the same word for electrum and amber (color similar?) which as some sort of electrical properties...which is were we get the word electricity. i didn't know that! neat!
