THE KEY DATE! The availability of 1878-S half dollars in any grade is far less than even the mintage of 12,000 pieces would indicate. Circulating coinage was heavily used and consumed by the booming California economy of the late 1870's. Consequently, the few 1878-S half dollars that entered circulation were quickly worn and eventually discarded. It is estimated that 60 or so coins are known. This specimen has remarkably clean surfaces for a heavily circulated Seated half dollar. Even wear is seen over the design elements, and the lighter gray motifs are surrounded by deeper gray accents at the margins. Ex: Old West and Franklinton Collections (American Numismatic Rarities, 8/2006), lot 642, where it brought $34,500.