Doubts On The Authenticity Of A Thrace Tetradrachm

Your question re authenticity seems in part to be driven by doubt about the alloy used.

That being the case, it would be prudent to have it checked using an XRF* instrument, checking for a mixture of trace elements, not silver. If it is made of a modern silver the alloy, it would be 'pure' having say, silver and copper only in the alloy.
The ancient Greeks did not have electrolytic metal refining technology available to them.

From the pictures, style looks OK, but that is easily reproduced using pressure casting.

Weight for this coin should be around 16.6 + or - about 0.3 grammes.
Persian weight standard used at this time.
Later coins are a bit less in weight using (I think **) a different weight system.

It may be worth making inquires a a PROVABLE provenance.
Who sold it, proof of where they got it from, auction records etc.


* = X Ray Florescence, a technique for analysing the proportion of elements which make up a substance.
Any bullion or scrap jewelry dealer worth his salt should have a hand held XRF instrument.

** I have not researched this, therefore my theory only.

You're right. Actually, I bought this coin before I discovered "Coin community"... The two images match perfectly well. I would rather send back this coin to the seller...

Thnk you for your advice, as ever very helpful