Remarkable transformation of Himera Didrachm, but is it real?

Howdy folks, Several weeks ago I happened upon a "great deal" for a lightweight silver Didrachm from Himera in Sicily and immediately purchased it before anyone else could. I bought other BIN items from the seller at awesome fire-sale prices and have no concerns about their authenticity, though I'm certainly no expert. Some of them look to have been interred in a marine or at least a salty context, which may have been the case with this didrachm.

Here's the disgusting hideous dirty coin as-pictured by the seller, covered in thick horn-silver and some sulfide with the pale blotches being broken horn silver nodules. I couldn't make out a trace of the "HIMEPA" ethnic that should have been in front of the rooster. The weird sharp edges on the rim gave me some pause but were just thick flaky horn-silver deposits easily dispatched with a scrape of the thumbnail:



I only had a few seconds to make my decision as it had just been listed and other sharks were circling, so despite the apparent issues I figured that 50 bucks shipped could be risked on the coin. I have a hard time resisting tasty ancient crabs.

Here's the coin shortly after it arrived. I had already started poking and scraping away at the encrustations and strange silver growths under 20x magnification when it occurred to me that before-pictures should be taken:



Under 20x magnification the freshly revealed surfaces were "frosty" and crystallized, with larger crystalline zones apparent in some areas. Thankfully the actual devices and fields seemed solid and largely unpitted, a blessing I wasn't expecting. Some deposits were too tenacious for my frequently-resharpened hard bamboo skewer so with the apparent integrity of the original surfaces informing the decision I brewed up a batch of boiling baking soda water and aluminum foil to treat the coin in. It fizzed more than any other silver coin I've treated in such a manner so I only kept it in for about 20 seconds, then washed with soap and water.

That quick treatment did the trick and then came several hours of picking-away at the softened dirt and horn-silver crusts and nodules. The surfaces were all rather frosty so after the crud was removed, some light rubbing with the bamboo skewer helped tamp-down and smooth the (microscopically) rough surfaces.

The crab shows some "doubling" so die-shift or double-striking may have occurred. The result, at least when compared with the original pictures I based the decision to buy off of, was absolutely awesome:



But then doubt set in, as the 20mm wide and clearly silver didrachm was only 6.58 grams.

I've never seen such a dirty crusty corroded ancient silver coin be shown to be a fake before, but I'm a noob and figure the forgers will always try to stay a step ahead of the Prokopov's of the world.

Here's an apparent obverse and reverse die-match (perhaps a difference in die-states but they seem to match pretty well):


Bertolami Fine Arts Auction 6 Lot 199. Sicily, Didrachm,Himera, c. 483-472 BC, AR, (g 8,09, mm 17, h 10). [HIMEPA], cock standing l., Rv. Crab. SNG ANS 157; SNG Copenhagen 302-303.Very rare. Good very fine/about extremely fine.

From: https://www.sixbid.com/en/bertolami...ns/581750/sicily-didrachm-himera-c-483-472-bc


So what do you think? An underweight flan that somehow got through but otherwise legitimate? Or are there known fakes of this style that I've overlooked?

Thanks for looking!

 

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I'm no expert of this topic either, but you mention that it showed signs of crystallization. I understand that the crystallization process can significantly reduce weight. I don't feel qualified enough to say whether or not that's the situation here or not though! See https://www.cointalk.com/threads/an...denarius-go-on-a-crystallization-diet.238550/

Also, as you'll see from reading the thread I linked too, if it's heavily crystallized, don't drop it!

 

It came out looking very nice by the way! I wouldn't have seen that potential. If it is genuine (fingers crossed), you did well

 

Turned out great. I have the litra version


Silver litra
Akragas (Agrigentum, Sicily, Italy) mint. Weight 0.552g, maximum diameter 10.2mm, die axis 45o, c. 450/446 - 439 B.C.; obverse AK-RA (clockwise from upper right, reversed Latin R), sea eagle standing left on Ionic capital; reverse crab seen from above, ΛI (mark of value below). SNG Cop 47; SNG ANS 989; SNG München 76; BMC Sicily p. 9, 50; HGC 2 121 (R1). EF, dark glossy toning, obverse double struck, some die wear.

 

Fantastic work. I would say the reduced weight is due to crystallization

 

While the crab looks fine, I don't like at all the lettering of the ethnic nor the looks of the cock.

 

Wow, that cleaned up nicely. You did a great job. Hope you get good news on authenticity.

 

Regardless of authenticity, you did a great job cleaning it up!

 

This may be also a point of concern; if indeed the coin was covered with original encrustations or horn silver, it shouldn't have cleaned that easily....

 

the result doesn't look right to me. search for "himera crab" on cng and see what I mean

 

Thanks for the comments everyone, this is certainly an ambiguous head-scratcher.

Yep I'm a straight, red-blooded man too. I don't have enough experience to know what does or doesn't look right with Himera didrachms, but if you check the BFA auction link and blow-up their coin you'll see that the ethnic is of the same font with same spacing, and there are the same number of feathers in the same orientation on the chicken too. It looks weird to me also but the loss of the surface layer of original silver and patina likely contributes to the uncanny appearance.

Who said it was easy? It took hours under 20x magnification even after dissolving the sulfide "glue" helping to hold the deposits together. I've been building experience cleaning crusty bronzes and dirty silver so have gotten better and faster at it but the task generally isn't ever an easy wham-bam-done sort of process unless the problem is only splotchy sulfide.

I have less experience with tarnished, dirty or horn silver encrusted AR coins as most of them are cleaned before reaching market but have picked away at the re-deposited silver encrustations on several coins which is softer and more brittle than the host silver and flakes or mushes off in generally predictable ways. I can upload comparison pics too but the difference isn't as dramatic since they were already mostly cleaned and silvery when obtained.

Yeah, the rooster side makes me a bit uneasy when coupled with the low weight, *if* genuine it must have been quite high-grade when lost/buried. Most of the Himera crab/cock didrachms I looked at are stylistically different but the BFA example I linked to seems to be a die match, just with more wear and mushing-down of the feathers. That said, a transfer-die of a better example could have been made and the die refined in areas (like the fatter cockscomb on the head).

Has anyone seen known fakes before with such measurably thick crud and deposits of re-crystallized/deposited "horn silver" (or whatever it technically is)? If so it's an alarming development!

 

BFA aka ACR in the past is not a good venue to benchmark coins on their authenticity

Let's see if the Deus ex machina (@Barry Murphy) intervenes to solve the tragedy

 

I have seen similar crud on fakes, designed to hide short comings in style--and the style of the cock is quite bad. I think this is a modern fake.

 

Sweet!

 

I've had this post bookmarked to see the final verdict: is the coin in question a modern fake, disguised with horn silver, or is it genuine?