An X-Frame Chair is a chair or stool built on a crossed, scissor-like frame, a form derived from the ancient curule and Savonarola seat, revived in Renaissance and later Regency and Empire furniture for its architectural, folding structure.
X-Ray Fluorescence is a non-destructive scientific testing method used to determine the elemental composition of metal objects, increasingly used by auction houses and conservators to authenticate silver, bronze and other metalwork.
Xing Ware is Chinese white-glazed stoneware produced during the Tang dynasty, among the earliest fine white ceramics made in China and a technical precursor to later porcelain development.
The Xuande Mark is a reign mark found on Chinese porcelain attributed to the Xuande period (1426-1435) of the Ming dynasty, a mark frequently copied on later wares as a mark of quality rather than a true indication of date, requiring expert authentication.
