This came into a coin shop I frequent, and they asked me for information and authenticity. My research showed that it is an Alexander III stater posthumously struck under Ptolemy I Soter. It was minted in Sidon, and the Sigma represents a date of 316/315 BC. However, I think this coin is fake. The shop said it weighed 6g (instead of ~8.6g - HUGE red flag, but could be an error). (EDIT: the shop told me wrong. It does weigh 8.5g) I did not find this coin in Forvm's fake database, but that is not conclusive evidence. The way Alexander's name is written, as well as some of Athena's freatures looked odd to me. I'm not sure how the color looks, but I presume it is much more gold-like. It tested positive for good gold (electronically, not abrasively!) So are my conclusions correct, or am I just paranoid?
I can understand your conclusions and I'd be of the same opinion. This listing of https://www.acsearch.info/search.htmlterm=alexander gold stater sidon&category=1-2&en=1&de=1&fr=1&it=1&es=1&ot=1&images=1¤c seem to span various styles and even similar inscriptions. I'm still as uncertain as I was a moment ago. Perhaps @IdesOfMarch01 or @AncientJoe can be of some real help....
Although I once owned an Alexander III stater, I have just a small amount of knowledge about these coins and cannot really evaluate its authenticity. Here's a little more background on this type of coin: Ptolemaic Kingdom of Egypt. Ptolemy I Soter AV Stater. In the names and types of Alexander III. Sidon, circa 316-315 BC. Head of Athena right, wearing crested Corinthian helmet decorated with a snake / Nike standing left, holding laurel wreath and stylis; S to left, AΛEΞANΔPOY to right. Price 3503; Muller 1321. Here's another example of this coin: Alexander III staters are readily available -- ACSEARCH lists over 3,000 of them -- although I found only about five with this particular reverse. Comparing the OP coin with the examples found on ACSEARCH doesn't show any alarming differences or similarities, and if its weight is around 8.6 g., it's the correct weight. To my untrained eye, nothing raises a red flag other than the color in the OP photo, which I assume doesn't accurately represent the coin's actual color. This is a fairly valuable coin ($3,000 - $4,000 minimum in this condition) and would be worthwhile having authenticated by an expert.
Is the obverse field slightly concave or is that just the photo? Both sides concave would be a red flag.
The strike (if in fact that was struck at all) looks soft and mushy to me on places like Athena's lips and hair strands, as well as Nike's left thigh on the reverse, which is particularly blobby looking on the upper portion where it meets her garment. It just looks "off" to me, though I lack the experience to say anything definitively.
I'm pretty leery of this coin: both sides look off. Granted, there is a wide variety of engraving on the countless dies of Alexander the Great staters but the strike abnormalities which are bothering @lordmarcovan bother me as well. The pictures leave a lot to be desired but I'd want an in-hand inspection (or slabbing by NGC) to check it.
Yes. Though much has been made of the fact that NGC Ancients does not guarantee authenticity, I do find them a useful "screen" and second opinion, since they will bodybag any coin they cannot verify the authenticity on. There is also the person whose opinion in ancients probably carries the most weight of any one individual in the marketplace: David Sear. Is he still offering an authentication service? Edit: aha! The answer to that last question seems to be "yes". It would probably be worth the fee to get one of Sear's ACCS certificates for a coin this potentially valuable. (*In my cursory examination of that webpage, I did not see any statement of what happens when he determines a coin is fake; i.e., how much of the fee - if any - is refundable in that event. Probably none.) Unfortunately, I do not hold out much hope for this one. The more I look at it, the more "off" it looks to me. But I'll defer to those with more expertise and experience. Gold staters are out of my league.
In this case, the obvious answer is to say that, although it is possible to condemn a fake coin from a photo, it is not possible to certify an authentic one without having it in hand.
