We know from a recent survey of Lydia that some 90% of these tumuli showed signs of looting. We know that this kyathos surfaced in the mid-1970s when parts of the Lydian haul were appearing on the market.
These points issues raise several issues.
Bonham's is a member of the Antiquities Dealers Association (ADA). Item 2 of the Code of Conduct states:
I undertake not to purchase or sell objects until I have established, to the best of my ability, that such objects were not stolen from excavations, architectural monuments, public institutions or private property.
So has the due diligence process taken place so that is can be demonstrated that this piece of silver was not removed illegally from an archaeological site - and specifically a burial tumulus in Lydia, Turkey?
Making a direct parallel in the sale description to a piece from the "Lydian hoard" would suggest that the thought had gone through the mind of the cataloguer at Bonham's. And if this did not raise concerns, should it have done?
But there is more. The estimate for the kyathos is "£12,000 - 15,000". And this is when point 3 of the ADA's Code of Conduct comes in:
It is a condition of membership that all goods acquired at the purchase price of £2,000 or more be checked with the Art Loss Register, or any other comparable stolen art database, unless they have already been so checked.
So presumably Bonham's has checked with the ALR. Is that correct? But, as I have discussed elsewhere, the ALR will indicate if the object has been stolen from, say, a private collection in Knightsbridge, but not if the item comes from a previously unknown and unrecorded archaeological site.
Both the ADA and ALR are seen by Sir John Boardman as examples of "good self-regulation". Is the sale of this piece of Lydian silver a test? Will the ADA and ALR be raising questions?