A British Museum 1992 analysis of the silver copper alloy gave an approximate composition of 40 silver, 42 copper, 10 tin, 2-3 zinc, 2-4 lead, together with traces of iron and gold.
Cf. L. Webster and J. Backhouse, The Making of England: Anglo-Saxon Art and Culture, AD 600-900, The British Museum, London, pp. 223-225, no. 178 for two similarly ornamented Pictish or Anglo-Saxon(?) silver-gilt scabbard chapes from the St Ninian's Isle hoard, Shetland, Scotland; and no. 179, for an Anglo-Saxon silver-gilt runic mount terminating in an animal's head, found in the River Thames. The mount in the above lot also finds parallels in some of the stylized motifs of Irish animal style, cf. M. Ryan (ed.), Treasures of Ireland: Irish Art 3000 B.C.-1500 A.D., Royal Irish Academy, Dublin, 1983, pp. 129-130, no. 51d, for a 9th Century A.D. silver-gilt pseudo-penannular brooch.