A riza (Russian: риза, "robe") or oklad (оклад, "covered"), sometimes called a "revetment" in English, is a metal cover protecting an icon. It is usually made of gilt or silvered metal with ornate bas relief technique. 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 art, the Russian term is often applied to Greek icons; in Greek the term is επένδυση ("coating"). Icons are described as επάργυρες or επίχρυσες: silver-covered and gold-covered, respectively.