The bowl of this unique vessel is of heavy cast bronze, and clearly made especially to accommodate the precious porphyry lid, of which the shape is typical of the stem vases carved in Rome in the first half of the 17th century.
While the Romans mined porphyry on an industrial scale for three centuries and more, the Byzantines recycled it on a post-industrial scale for much longer. The Ottomans inherited a vast store of the stone once they had conquered Constantinople, and slices of it appear everywhere in the floors and walls of the great mosques and grand buildings of the city. It had lost none of the imperial associations that made it the most emblematic stone of late Antiquity, its hardness equated with virtue and its colour with royalty. The technique of carving porphyry was rediscovered in Italy during the Renaissance, but not elsewhere, which probably explains why such care has been taken to re-use this elegant curved Roman lid in an Ottoman context. It has been suggested that the crescent finial has a political message of the triumph over Rome and Byzantium, but it could also be a message of understated elegance!
Published: Dario del Bufalo, porphyry, Red Imperial Porphyry, Power and Religion, Allemandi & C., Turin, 2012, V47, p. 145.