Karakhanid coin strips

[Figleaf]

I came across a surprising exhibit in the coin department of the museum of the Ark in Bukhara.  The label of the two strips speaks for itself.

What is amazing about this is the technology used. The strips were of equal thickness throughout, suggesting that around 1100 AD, the Karakhanids had mechanical rolling equipment and machines to cut perfectly round flans from a strip as well as a technique to strike perfectly centred coins. The oldest European mint with that level of technology was in Segovia (see here and here), albeit using water power. It is not clear to me if the Karakhanids used water power, but it sure looks like they were 500 years ahead of Segovia!

Peter

[THCoins]

Very intriguing artefacts !
Would you think the karakhanids punched and struck their coins in one blow from these ? If so that would explain why these coins are always so paper thin. That may have been the compromize they had to make because the technique probably was not yet advanced enough to make full thickness coins.

[capnbirdseye]

They would have to make a special die to cut and stamp at the same time I would think, they would also have to hope the reverse die underneath the copper strip was lined up properly.
It's hard to tell from the photo but the strips looks thicker than I would expect for paper thin Karakhanid coins, they are often brittle and can be snapped in half but that may be the result of centuries of hardening.

[Figleaf]

It may be time to re-visit this thread. Yes, the strips were thicker than the coins. Yet, the flans had already been cut from the strips. That's puzzling. If the coins were struck and cut in one blow, they would have been as thick as the strip and the knife would have operated as a collar. If the flans were cut, then struck - a likely scenario - how are Qarakhanid coins always perfectly centred? The problem is that striking expanded the coins. They were not struck in a collar. How do you centre AND leave room for expansion?

Peter

[capnbirdseye]

There is always the possibility that the items in question were not actually Karakhanid, many museums of multiple local interest items would probably not have a coin expert and even if they did it's easy enough to come to the wrong conclusion

[Figleaf]

Everything is possible, but it is not likely. There is a lively interest in Karakhanid coins in Uzbekistan. The "official" expert is Mr. Edvard Rtveladze, but the coins are available in the shouks, collected and studied. The major museums are in Tashkent, but the Ark of Bukhara is more than a provincial museum. After the national museum, it had the largest coin collection on display I could find (I didn't have a chance to see to collection of the central bank). In UK terms, the Ark is to the national museum what the Ashmolean is to the British museum.

Intriguingly, the Bukhara mint was in the Ark. It is therefore quite possible that the strips were found in the Ark. If so, it is practically certain that Mr. Rtveladze had a look at them and he probably identified them.

Peter