What are these marks? They look like a drill or punch marks. I see them in mostly this position but I have see them in the head of Gordian and other places. Are they some kind of test mark?
Hi @edteach, See Doug Smith's page at https://www.forumancientcoins.com/dougsmith/pit.html This was also discussed before here: https://www.cointalk.com/threads/so-called-centration-dimples-annoy-me.310056/ - Broucheion
I surely am no expert. I look like a control mark so that the planchet doesn't move during the strike.
As stated above they are centration dimples created during the minting process. They are typically found on large bronze coins but have also been found on other denominations and metals.
This is very common for this series of coins apparently. I saw this with three I looked at before purchasing with my local German dealer. His English and my German were not compatible with the details, but he indicated this was normal. It's a provincial thing. MOESIA INFERIOR. Odessos. Gordian III with Tranquillina (238-244). Ae. Obv: AYT K M ANT ΓΟΡΔΙΑΝΟC AVΓ CE / TPANKVΛΛEIN. Laurate, draped and cuirassed bust of Gordian right vis-a-vis diademed and draped bust of Tranquillina left. Rev: OΔΗCCEITΩN. Athena standing facing, head left, holding owl and spear; shield at feet to left; E in left field. Varbanov 4559. Condition: Very fine. Weight: 12.89 g. Diameter: 27 mm See the series below for the marks: https://www.acsearch.info/search.ht...de=1&fr=1&it=1&es=1&ot=1¤cy=usd&order=0 **Found my actual coin sold in 2014. Don't have premium to see what it cost then though. https://www.acsearch.info/search.html?id=2289039
It is a mystery as to why some coins have them and some don't. Here is one of my limes (Zinc) denarius of Gordian III that has a dimple. Here is one of my bronze Sestertius of Gordian III that doesn't have one.
Jean Hourmouziadis has interesting data on centering marks on his website, though I'm not sure if it's ever been published (recording whether they're visible on the obverse, reverse, both). Quantified in interesting ways, though. For various cities: Cilicia, Soloi ; Phrygia, Prymnessus ; Lycaonia, Derbe (just results, not coin photos) ; many others in these links. Here's a favorite of mine. Sometimes these ones from Thessalonica have a dimple-inside-a-dimple structure, and you can see the grooves from the rotation (although hard to focus enough to show in photos). There's a matching one behind the eye, but the high relief meant it was certain to be almost obliterated when the metal was forced into the die: Roman Provincial / Greek Imperial. Philip II (Caesar), under Philip I (Augustus). Macedon, Thessalonica AE Tetrassarion (26.5mm, 11.23g, 7h), Second Pythian Games issue, struck circa 246 CE. Obv: · ΜΑΡ · ΙΟΥΛΙΟϹ · ΦΙΛΙΠΠΟϹ · ΚƐ (·) – Mar(cus) Julius Philippus Ca(esar). Radiate, draped, and cuirassed bust of Philip II facing right, seen from rear. Rev: ΘƐϹϹΑΛΟΝΙΚƐΩΝ ΝƐΩ / ·ΠΥΘΙΑΔΙ· / ·Β· – Of the Thessalonians, Neo(korate) / Pythian Games / #2. Temple (of Kabeiros?) with four side columns, on podium, seen in 3/4 perspective to right. Ref: RPC VIII (Temp.) 69113, ex. 6 (this coin); Touratsoglou (Thessaloniki, 1988) 62 (Philip II); Varbanov (vol III, 2007) 4740; Moushmov –. See also: Jean Hourmouziadis “Virtual Collection” SHH v3964 (this coin). Provenance: Ex-Dix, Noonan, Webb A7 (17 Mar 2009), Lot 1235; Pegasi MBS 22 (20 Apr 2010), Lot 383 (unsold, and numerous later Pegasi/VAuctions sales through 2020); CNG e-Auction 489 (7 Apr 2021), Lot 272 A lot of my Bithynian and Moesian Provincials have them. Here are a few from the Lindgren Collection that show dimples on both sides: [expandable thumbnails] These coins = RPC VI, 1225/1 (Moesia, Nicopolis) = HHJ 8.26.34.2 ; RPC VI, 2385/4 (Nicaea) = Lindgren 145 ; RPC VIII, 846/5 (Nicomedia) = Lindgren 177 Another nice pair from Moesia, Nicopolis: This coin = Varbanov 2258, ex Fischer, Kluger I don't think the Roman Imperials tend to have them do they? I would be interested to see examples from the Rome mint, if known. (I've seen them on 1st century "Imperial" -- Provincials with Latin legends -- from the Thrace mints.) They're generally seen on Ptolemaic & Seleukid coins, and Roman Provincial coins, especially Balkan mints (Thrace, Moesia, Macedon, etc.), some Asia Minor (e.g., Pamphylia) and Egypt, Alexandria. I don't think I've seen one on a Limes before. I don't think it's implausible, but I would want to consider other hypotheses for a few reasons: it's unusual to see one that off-center (since the purpose was probably to spin the flan on a lathe); especially since they're usually limited to larger flans (a certain size presumably required for spinning/lathing), but if they're known from denarius sized coins, I'd be interested to know; Also, if it is a centering dimple, that's strong evidence a coin is struck, rather than cast, as Limes are often assumed to be. I'm not certain how universal casting is thought to be for them.
Based on microscopic enhancement I was able to confirm the Limes denarius is a centration dimple due to the circular scratches within the indentation. These are identical to my other coins that have centration dimples. Some of my larger bronzes are offset like the denarius, however most are centered. I haven't seen any on Roman Imperial silver coins but I have seen them on some Lime denarii like mine. Not sure why they occur only on Lime coins and not silver, perhaps due to crude minting methods in the areas that issued Lime coins or perhaps that's the coining method they were familiar with.
The circular scratches also appear in piercings (attempted or the edges of successful, since pierced coins were typically drilled not hammered). If there are other similar Limes, I would find that convincing. I've never noticed or found one, having looked at a lot of them. If you have or come across any images I would be grateful if you'd share them. Incidentally, I do own one small Seleukid serrate bronze with an apparent centering dimple, so apparently it was practical to use this technology on small flans as well as large, though it seems not as common (unless they just tended to be obliterated when striking small ones): Seleukid Kings of Syria, Antiochos IV Epiphanes & Laodike IV Serrate AE (17.5mm, 4.3g, 1h). Ptolemaïs (Ake) mint, struck circa 173/2 BCE. Obv: Veiled and diademed bust of Laodike IV right (monogram behind, beneath sand?). Rev: BAΣIΛEΩΣ ANTIOΧOY. Head of elephant left; galley prow behind/right. Ref: SC 1477.2; HGC 9, 686; cf. SNG Cop 184.
Not a video, but this series illustrates it pretty well with text and diagrams. Dave Welsh's (Temecula, CA) ClassicalCoins.com website no longer exists, so you have to see it in the Wayback Machine: https://web.archive.org/web/20150924041232/http://www.classicalcoins.com/flans1.html Keep clicking "NEXT PAGE" (bottom left) from Flans1.html through Flans8.html. Flans5 is where it starts picking up, and you can start there if you have the basic idea, and Flans6 is where the diagrams start. Keep in mind, we're not 100% certain how they did it, and it's observed over about 500 years of coins across a wide geographic range, so there were surely improvements and variations in the tech. But this is the most plausible explanation of the observed data:
Here is another oddity. Most, if not all, Ptolemy bronzes have centration dimples. However I have a Ptolemy coin that doesn't have one: Here is a typical Ptolemy with the dimple:
What is the size? For the very large ones (e.g., the 40mm, 60-90grams types) it is pretty unusual to see them without any remaining sign of the dimple (sometimes on one side). For the smaller ones, though -- e.g., Obol size, ~8-20g or so, 20-28mm, and under, e.g., Hemiobols -- I think it's less unusual. They presumably all had the marks, small or large, but it was a question of whether the strike obliterated it. On the smaller, lighter ones, the dimples were less deep, and their evidence was easier destroyed. For a big one, though, the dimples were a lot deeper, so it would be a lot harder for the strike to completely remove it (especially on both sides).
It's an AE26 - 26 mm / 14.6 g - attached is a "zoomable" photo. There doesn't appear to be any trace of a dimple on either side of the coin.
Hi @-monolith-, This is not odd at all. As explained in Lorber’s CPE and elsewhere, Ptolemaic coins made before the major coinage reform of coin series 3 (ca 260 BCE) have no dimples, while most of those afterwards do. Lorber: “The reform of the bronze currency also introduced a change in fabric: a circular indentation appears near the center of the flan, usually on both sides of the coin. Metallographic studies have determined that these cavities were not a feature of the cast flans but were added before striking, so that the planchet could be turned on a lathe while its two faces were smoothed. This painstaking procedure was probably necessitated by the introduction of very large denominations, to ensure that the devices would be clear. Ancient moneyers obviously encountered difficulties in striking large flans and the process of striking affected the flan to only a few millimeters' depth.” [NB, footnotes omitted.] - Broucheion
I wonder if the process of turning down the planchet, that the idea was to turn it down to the level of the dimple? This would explain why some have a dimple and some do not. Has anyone ever found a planchet not struck with the dimple?
Most coins and planchets never had one because this process was only used at certain mints. (Different mints often produced flans in radically different ways; even the same mint at different times.) So the vast majority of unstruck flans never had them. (Judaean flans, e.g., usually have a protrusion at the center on one side.) But if you mean unstruck Ptolemaic flans (i.e., after 260 BCE) specifically, to my knowledge they're very rare and only a few are known. (I don't have the Lorber books though; she may report more.) A few known examples are reported by: Faucher, T. 2017. ‘Coin Minting Techniques in Ptolemaic Egypt: Observe, Analyze, Recreate’. Notae Numismaticae, XII. pp. 71-90. It's not well-illustrated & I need to re-read it, but I recall that it sounded like rough central dimples may have been part of the original planchet cast, which would mean they were there from the start on unstruck Ptolemaic planchets (at least the ones that ever had them). The rotation would've then altered their shape once actually put to use on the polishing lathe. From their placement around the coin, it's clear that other mints only added the dimple after the flan was created (but still before the striking process, so the blank flan could be polished). Such as the Moesian and other Balkan ones above (e.g. the Gordian & Tranquilina types). The goal was definitely NOT to polish/lathe the surface down until the dimple was gone. (I'm not sure how that would even be possible since the dimple is how the pin holds it on the lathe/wheel, and the more you spin/polish, the deeper the pin digs into the hole.) The dimple would sometimes be obliterated when the coin was finally struck, but that was almost incidental. The mint-masters don't seem to have particularly minded them being there, since they're ubiquitous on some types.
