Important devotional artifact made of green jade, amethyst and coral beads. The Cao Zhu is a rosary based on Buddhist models that was introduced in official ceremonies by the Qing dynasty emperors, as recorded in the codex "Illustrated Regulations for the Ceremonial Paraphernalia in the Qing dynasty" by Huangchao Liqi Tushi. The manual regulated the number of spheres, extensions and materials that could make up this peculiar artifact. The importance of this accessory in official ceremonies is illustrated by a portrait of Emperor Yongzheng, now at the Palace Museum in Beijing, a painting in which the emperor wears a Chao Zhu of pearls.