Matteo de' Pasti, ‘Leone Battista Alberti, 1404-1472, Architect and Writer on Art and Science [obverse]’, 1446/1450, National Gallery of Art, Washington, D.C.
overall (diameter): 9.34 cm (3 11/16 in.)  gross weight: 205.24 gr (0.452 lb.)  axis: 12:00