What is "cosmatesque"

Cosmatesque, or Cosmati, is a style of geometric decorative inlay stonework typical of the architecture of Medieval Italy, and especially of Rome and its surroundings, and derived from that of the Byzantine Empire. It was used most extensively for the decoration of church floors, but was also used to decorate church walls, pulpits, and bishop's thrones. The name derives from the Cosmati, the leading family workshop of marble craftsmen in Rome who created such geometrical decorations. The style spread across Europe, where it was used in the most prestigious churches; the high altar of Westminster Abbey, for example, is decorated with a Cosmatesque marble floor.