Hello everyone, I have been a long-time researcher of Ottoman coinage from the reign of Sultan Selim I. However, I have never actively collected coins. My work has focused almost entirely on typology, legends, and designs, so I lack hands-on experience with issues such as surface characteristics and authenticity. For example, I would not be confident distinguishing a struck coin from a cast one using a loupe. I am currently conducting type research and had a question regarding the coin shown above. From what I can determine, this is a very rare piece, and the two coins illustrated here are the only examples I have been able to locate. They appear to be a double-die match (which is not unusual in my experience, as this Sultan only reigned for 8 years, and the above coin was likely minted in a 6 years period as the title Shah was likely used because he defeated the Safavids in 1514). The better-preserved specimen was sold by Gorny & Mosch and later by Stephen Album, where it was graded by NGC. The lower-grade example was sold by Stanley Gibbons Baldwins and, if I recall correctly, realized approximately £500. I believe the two coins appeared at auction within roughly five years of each other. The reverse type itself is known (reverse is the side with the knotted designs) but what makes these coins exceptional is the obverse, which I have only ever seen on these two examples. The higher-grade coin was also published in Atom Damalı’s important series on the Ottoman Empire, which is where I first encountered this type. What particularly caught my attention is an unusual surface texture on the reverse, located in the lower-right area. The texture appears somewhat rippled and is not present elsewhere on the coin. I have noticed several exact similarities in this textured area between the two specimens, although there are also clear differences. Because of these differences, I am inclined to rule out transfer-die hammered forgeries, as such pieces would be expected to match exactly. I would appreciate your opinions on whether this texture is consistent with a die-related issue or whether it might be cause for concern.
That's a pretty specialized question. I hope you can find someone to help, but alas, that person is not me.
Welcome to CT @dtaso1516. Firstly, I must admit I know nothing about the design and history of these coins and in fact couldn't identify the obverse from the reverse! I assume that the gold standard of these coins is high so we can eliminate chemical reactions such as oxidisation and leaching. I used to run a non-ferrous foundry business for many years so know a little about dies and their structure and wear albeit we were casting not forging. The "rippled" or granular texture you noticed in the lower-right area of the reverse (the side with the knotted designs) is a known phenomenon in hammered coinage. Based on your description and the visual evidence, here are some of my ideas but I am no expert but there will be someone here for certain who is. I'll simply set the ball rolling for you. Die Rust or Deterioration: Even dies made of hardened steel were susceptible to oxidisation if stored in damp conditions. When a die rusts, the steel surface becomes pitted and when a coin is subsequently struck the gold is formed into these tiny pits in a raised or granular texture on the finished coin. The fact that you have die paired could intimate that the die was corroded in that area and used on both planchets. Die Fatigue: As dies reach the end of their life the constant stress of hammering causes the steel to flow or develop microscopic fissures. This can manifest as a pebbled or orange-peel texture particularly near the edges where the pressure is greatest. Planchet Imperfections: In the 16th century, gold planchets were prepared by hand. If the gold was not perfectly refined or if the planchet was poorly cast before being hammered, it might retain internal gas bubbles or "sponginess" that surfaces under the force of the strike. I don’t think this is the case as you appear to have a unilateral issue in the same quadrant. Environmental Factors: While gold does not corrode in the traditional sense, it is a soft metal. If the coin was buried in a high-energy environment (like a riverbed with abrasive sand), it could develop "micro-pitting." However, this usually affects the entire surface rather than just one specific area of the die. I have several “Tiber recovered” roman coins and their surface commonality lend me towards modern chemical intervention for “improvement” and attracting the romantic unwary (me!). These all exhibit a mottled surface. I also collect shipwreck coins and sometimes we see a coin that is more eroded on one side or quadrant than the other. This is explained by the possibility of only one side being exposed to current and abrasion facing outwards or perhaps half a coin protruding from coral or sand. I have a book on the metallurgy of coins and many British Numismatic Journals which often contain articles on metallurgy. If no one gives you better answers, when I have time, I will do a little research and revert. I suspect a die issue, third party grading gives comfort about the obvious such as casting on the first coin and the quality of the dealer should give comfort on the authenticity of the second coin. They have been around for 150 years and it would be unlikely they would let a forgery slip through the hands. It happens of course but given the provenance and reputations at stake, unlikely. Had it been acquired from certain other auction houses I would not register such positivity. Thank you for raising an interesting first post!
