This unusual vessel is of a form which appears not to have any parallel in the known works in rock crystal of the period. Hardstone inkwells are known, but not in crystal and not double examples.
The vigorous and clear carving is found on a number of other crystal vessels including a bottle sold in these Rooms 28 April 1998, lot 379. The decoration on these items is ultimately derived from the so-called "bevelled" style which has its origins in the stucco decoration found at the Abbasid city of Samarra. Present consensus attributes these items to Fatimid Egypt, based on the evidence of the Fatimid treasury accounts related by the Mamluk author al-Maqrizi and a number of surviving items inscribed with the names of Fatimid caliphs and officials. These are a ewer in the Church of San Marco Venice in the name of al-'Aziz (Curatola, G.: Eredità dell'Islam, exhibition catalogue, Venice, 1993, no.61, pp.153-4); another in the Palazzo Pitti in Florence in the name of the son of the Fatimid general Jawhar al-Siqili (Curatola, G.: op. cit., no.62, p.155), and a crescent in the Bayrisches Nationalmuseum Nuremberg in the name of al-Zahir (A. Shalem: Islam Christianized, Frankfurt-am-Main, 1998, no.72, pp.222-223, pl.15, p.379). A number of related and also simpler pieces in terms of the decoration are to be found in European church treasuries.