Riza

A riza or oklad, sometimes called a "revetment" in English, is a thin metal cover protecting an icon. It is usually made of gilt or silvered metal with repoussé work and is pierced to expose elements of the underlying painting. It is sometimes enameled, filigreed, or set with artificial, semi-precious or even precious stones and pearls. Although the practice of using rizas originated in Byzantine... (Wikipedia)