Al-Yatima

Al-Yatīma (Arabic: اليتيمة, meaning 'the orphan', apparently named for its unique size) was a pearl 'considered to be the most celebrated Islamic jewel of the Middle Ages'.[1]^: 43 How it came into Muslim hands is not clear: it might have come from Visigothic Spain or the Sasanian Empire during the Islamic Conquests.[1]^: 43 During the Umayyad period al-Yatīma was displayed in the Dome of the Rock in Jerusalem; it (or another jewel believed to be it) came into Abbasid hands and became part of their royal insignia, mounted on the crown of al-Mu'tasim (r. 833-42 CE).[1]^: 49 From the tenth century onwards, its history is uncertain.[1]^: 50

It has been suggested that the German idea of der Weise ('the orphan'), a precious stone in the crown of the Holy Roman Emperor, was inspired by Arabic traditions of al-Yatīma.[1]^: 50–52