Rock crystal is made up of pure quartz crystal and was shaped by skillful craftsmen whom the Fatimids valued greatly. “Of all the rock crystal objects manufactured by Fatimid artisans, the Fatimid rock crystal ewers are considered among the rarest and most valuable objects in the entire sphere of Islamic art. Only five were known to exist before the extraordinary appearance of an ewer in a provincial British auction in 2008 which was later sold at Christie’s last October.