 All parts of the hilt are covered with golden plates , which are engraved with sharp or rounded styli and decorated with niello , or black metallic inlay that contrasts against the golden background . Each plate is 1 mm ( 0 @.@ 04 in ) thick and made of about 18 @-@ carat gold . The niello designs include inscriptions written in late Romanesque majuscule ( with some uncial additions ) , Christian symbols , and floral patterns . The floral ornaments are in negative , that is , golden against a black , nielloed background . 
