This bookmark is made in Norway by David Andersen. It is marked with his hallmark and 925. The David Andersen mark is described by the firm as a hammer and tong design, with the hammer in the center. It came into use in 1888. Norwegian law requires the degree of fineness to be followed by the letter S for silver. David Andersen chose to incorporate the S into their punch. Often the S was crossed by a diagonal line. The top of the bookmark is plique-a-jour with green and blue enamel. The date is 1890 - 1910.