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!