high-tin bronze, cast, with engraved and chip-cut surface decoration
With its fan-shaped thumbpiece and pedestal base, the shape of this cup (though not its size) derives from a Roman bronze vessel type, well represented in finds in northern Europe. By the 7th to 8th centuries this type of vessel had made its way east to Tang China and was there imitated in precious metal. When un-patinated, high-tin bronze gives a striking approximation to the colour of silver gilt. However, it was expensive to manufacture and the alloy was so brittle that only a small range of decorative techniques, especially chip cutting, could be applied.
J.M. Rogers, The Arts of Islam. Masterpieces from the Khalili Collection, London 2010, cat.19, p.43.