Sasanian help

Started by Desibot, July 02, 2021, 05:10:20 PM

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Desibot

Hi guys help I'd this please

Any help will be appriciated

Thankyou

Manzikert

It is an Arab-Sasanian coin from Eastern Sistan, but I'm afraid I don't know which of the various governors this might be yet, but I'll keep looking.

The various issuers are listed in Album's checklist as P75-89F

Alan

Manzikert

It is a coin of Qudama, c.770s AD, A-86 RR, see Zeno https://www.zeno.ru/showgallery.php?cat=6451

Alan

Desibot

Thank you Alan appriciated it

Figleaf

Strange surfaces. Would the flans have been cast in a stone mould? If so, they would have been too brittle for striking, but the design, with its smooth, broad and flat surfaces can't have been cut in stone.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Manzikert

I think the alloy of many these is rather base as they often show signs of roughness due to corrosion. I attach a scan of a specimen I have had for some time to illustrate. You also get similar surfaces on the multiple dirhems from Afghanistan which are also of rather dubious alloys, which can often have a rather 'crazy paving' surface, see enlargement.

They must have been struck on thin hammered blanks like the standard Sasanian coinage, and like many other Arab Sasanian coins they are quite uniform in thickness, and presumably struck with some force to flatten them so. I would assume the hammered blanks were annealed before striking to get rid of any work hardening.

Alan

Figleaf

Ah! That enlargement was an eye-opener. It shows that the raised parts are covered by "crazy pavement" (I like that!) also. Being struck in base metal is not enough for this effect, though. I have seen more low grade silver coins than I care to remember and this surface is new to me.

It is as though there are rivulets running through the surface. Perhaps the copper used had important quantities of yet another metal, more susceptible to corrosion and badly mixed, so that in time, it was washed out? In that case the rivulets should be quite irregular in direction. However, on the coin in the first post and on the enlargement, they seem to go from the centre to the edge, even straight through the raised parts, which would happen during striking. Perhaps the other metal had a lower melting point (lead?), the blanks were hot-struck and the metal inclusions were "squeezed out" by the strike? If so, the crazy pavement effect would be present even on coins that look as struck.

Peter
An unidentified coin is a piece of metal. An identified coin is a piece of history.

Manzikert

Perhaps the multiple dirhems were struck quite hot, and the top 'skin' of the flan cooled quickly: when struck the still almost molten 'core' flowed more and the 'skin' cracked as it was stretched.

I attach another enlargement of a coin where the lower field which contacted the die is actually very shiny, almost 'prooflike' in hand, whilst the relief which was less (or not) compressed by the die have the characteristic 'crazy paving' look. The edge has more radial cracking of the 'skin' than this centre.

From the few analyses I've seen the silver content can be from as high as 97% to as low as 55%, but I can't find any mention of large lead percentages: I'll have to look for further analyses.

Alan