Leaf from the Blue Qur’an. Iraq, Iran, or Tunisia, 9th/10th century. Gold and silver on indigo-colored parchment, 28.4 x 38.1 cm. Brooklyn Museum, Gift of Beatrice Riese, 1995.51a-b. Photo courtesy of Brooklyn Museum

The celebrated Blue Qur’an makes extravagant use of gold and silver leaf for the script, which was laboriously applied to approximately six hundred folios colored a deep, rich indigo blue. Like gold, indigo circulated widely along trans-Saharan trade networks. The origins of the Blue Qur’an are debated. Some attribute it to Abbasid artists working in Iraq in the early 9th century; however, a possible origin in Fatimid Ifriqiya (Tunisia) has also been proposed. Fatimid control of gold coming northward across the Sahara funded the caliphate’s expansion in the mid-10th century; Ifriqiya was an important terminus for these routes.