The niello, a preeminently important Russian technique of decorating silver, follows the print Naufrage by Jacques de Lajoue (1687–1761), published in Paris in 1736 and integrated into a pattern book. A copy was in Catherine's extensive library. The exuberant wave and shell-like rocaille formations perfectly illustrate the Central European Rococo style, referring to the turban snail's origins in the exotic Indo-Pacific Ocean. Related turban-snail cases bearing Chinese inscriptions document that they were imported into Russia from China, where they originally served as ceremonial wine cups.