Constans II, 641-668. Hexagram (Silver, 23 mm, 6.63 g, 6 h), Constantinople, 641-647. d N CONSTAN-TINЧS P P AV Crowned facing bust of Constans II, beardless, wearing chlamys and holding globus cruciger. Rev. DEЧS AdIЧTA ROMANIS Cross potent set on globe and three steps. DOC 48. MIB 142. SB 989. Good centering. Light scratches and marks, otherwise, nearly very fine.
From the Trausnitz Collection, ex Gorny & Mosch 134, 11 October 2004, 3236.

The hexagram was a short-lived large silver denomination that was produced in relatively large numbers under Heraclius, Constans II and Constantine IV. During the first reign of Justinian II limited numbers were produced but after that point the coin was only minted in extremely small numbers for ceremonial occasions.