Islamic glass disk weights are common through museums and private collections, although they are usually linked to Egypt due to their provenience or because they bear the finance directors names known to be active in Egypt. Egyptian glass weights have been largely studied, and offered a starting point for studies on the Syrian ones, while jordanian territory is yet to be investigated. Their use is broad and their interpretation not always certain, having usually lost their originally context: coin weights or monetary substitutes for copper and low-value currency, and later re-used tokens. Aim of this study is to analyse the origin, possible use, historical context and economic significance in exchange politics of a glass disk weight fragment from the excavation of the CF 35 in Shobak Castle, a great vaulted structure, built by crusaders and reused by ayyubids, located in the “monumental” area of the castle. It comes from the most recent layer, a thick level of sand and clay, covering the whole excavation area and dating to the abandon period. The item bears part of an inscription and a central design, it is therefore possible to establish a link to official coinage and patronage, and to deepen the knowledge of political and economic interaction of such a crucial area.