Watch List notes:

Attica, Athens, Tetradrachm, ca. 500-480 BC; AR (g 16,98; mm 22; h 6); Head of Athena r., wearing crested helmet decorated with chevron and dot pattern, Rv. AΘE, owl, with closed wings, standing r. with head facing; on l., olive twig with two leaves and one berry; all within incuse square. Seltman Group M & G; Asyut Group IV; HGC 1590.
Lightly toned, centered on a thick flan, somewhat porous, anyway about extremely fine - extremely fine.