In circulation, the Standing Liberty's date wore away quickly, and Mint engravers modified the design in 1925 to address the issue. The Standing Liberty quarter was discontinued in 1931, a year in which no quarters were struck. 90% Silver and 10% Copper.
This 1930 example is typical but a bit better than some listed here. Ungraded it does have a full date all lettering is intact if not all sharp.