Rock crystal spheres of this large size are rare. The largest, at around 32.8 cm., is now in the collection of the Smithsonian Institution in Washington, DC. The Smithsonian sphere was reportedly fashioned by Chinese lapidaries in Shanghai between 1920-1924, from a half-ton block of Burmese rock crystal. The second largest sphere is believed to be one in the collection of the University of Pennsylvania Museum of Archeology and Anthropology (accession no. C681A) measuring 25.4 cm. in diameter. It is said to have been made for the Empress Dowager Cixi (1836-1908) and was one of her prized posessions. Another slightly larger sphere, balanced on a wave stand very similar to the present stand, is in the collection of the Philadelphia Art Museum (accession no. 1944-20-2a,b).
The current sphere, like those above, was made entirely by hand in a laborious process. The final hand polishing, using finely powdered iron oxide, gave these spheres a luster rarely achieved using modern gem-polishing machinery.
Rock crystal carvings have long been prized by the Chinese, warranting a dedicated discussion chapter in collecting guides, such as the late Ming aesthete Zhang Yingwen's Pure and Arcane Collecting. Rock crystal symbolizes purity and perfection, while the sphere represents completeness and the infinity of space.