A hallmark is a symbol stamped on a piece of silver, identifying the silversmith and usually providing information regarding the location and date of manufacture, as well as the quality of the silver. Such marks, made up of abbreviations and tiny images, are often incomprehensible to those unfamiliar with them. The letters S and I, both singly and in combination, can take on many different meanings depending on the silverware's origin.
Siena Hallmark Abbreviation
Italian silver made after 1934 is required by law to be marked with the silversmith's registration number and province abbreviation in a cartouche shaped like a lozenge with clipped sides. Each province has a standard two letter abbreviation; silverware marked with the letters SI indicates that the piece was made by a silversmith registered in Siena.
International Silver Co.
International Silver is a conglomerate company, formed by the merger of over 20 smaller American manufacturers in 1898. Pieces produced by the company will often feature both the hallmark of the smaller company that actually performed the manufacture and that of International Silver itself. International Silver has used many different marks over the years, often made up of only the letters, IS, side by side.
Swedish Fineness Indicator
Swedish silver made after 1912 is stamped with five marks: the maker's mark, the city mark and the year mark all vary, as would be expected, but the remaining two are constant. Every piece has a triple crown mark, in a trefoil cartouche for silverware made locally or an oval for imports. The letter S in a hexagon also appears on every piece, indicating that its degree of fineness exceeds 830.
Individual Maker's Marks
Though a single letter I is rare among hallmarks, several makers have used marks that feature only the letter S. An S in a plain circle is the mark of the Shepard Manufacturing Co. of Melrose Highlands, Massachusetts, while an S in a winged circle is that of George W. Shiebler & Co. of New York City. An S between two outward-pointing triangles is the mark of the E.H.H. Smith Silver Co. of Bridgeport, Connecticut. The Frank W. Smith Silver Co. of Gardner, Massachusetts used a particularly distinctive mark: an S intersecting a crescent, upon which stands a rampant lion.