ISLAMIC, Time of the Rashidun. Pseudo-Byzantine types. Fals (Bronze, 25 mm, 5.65 g, 1 h), Arab-Byzantine type imitating a follis of Constans II, uncertain mint, circa AH 24/5-27/8 = AD 645-647. Crowned and draped bust facing, bearded, holding cross in his right hand;  Rev. Large M in center; to left, illegible legend; to right X; above, . T. Goodwin, 'An enigmatic early Arab-Byzantine coin type' in: Mélanges de numismatique et d'archéologie de Byzance offerts à Henri Pottier, p. 149, 53 ( same obverse die ). Very rare and with attractive earthen highlights. Very fine.