1923-S Standing Liberty Quarter. MS-66 (PCGS). This brilliant and beautiful example is nearly full in strike with bountiful mint luster. The modest mintage of 1,360,000 pieces accords the 1923-S key date status in the challenging Standing Liberty quarter series, especially in the finest Mint State grades, as here. An appealing specimen for the discerning collector. From the Collection of Silas Stanley Roberts, 1888-1966.