Iron with copper-alloy casing, 150 grams; 33.78mm. 9th-11th century. The piece is almost spherical but with flattened ‘poles’, made from an iron core with a copper-alloy outer casing. The weight of the piece is equivalent to around 20 ortugar. Such a heavy weight (5.3 modern ounces) would have been useful for commodities traded in quantity, or for heavier materials such as hack-silver. The physical shape of the weights and the system of metrology used are both based on the Byzantine model. Reference: cf. fig. 2 in Entwistle, C. Byzantine Weights in Laiou, A.E. The Economic History of Byzantium From the Seventh through the Fifteenth Century, Washington D.C., 2002. Published: Hammond, Brett. British Artefacts, volume 2 - Middle Saxon & Viking, Witham, 2010. Very fine condition.