Amadio da Milano, ‘Niccolo III d'Este, 1383-1441, Marquess of Ferrara 1393 [obverse]’, probably 1437/1441, National Gallery of Art, Washington, D.C.
overall (diameter): 5.36 cm (2 1/8 in.)  gross weight: 64.74 gr (0.143 lb.)  axis: 12:00