Tacitus. A.D. 275-276. AR double antoninianus. 2.96 gm. 22 mm. Antioch mint, 4th officina. His radiate, draped, and cuirassed bust right; IMP C M CL TACITVS AVG / Emperor standing right, holding eagle-tipped scepter, receiving globe from Jupiter standing left, holding scepter; CLEMENTIA TEMP around, Δ between, XI in exergue. RIC V.1 211. Extremely Fine; fully silvered. Very rare.

Ex Coin Galleries (21 July 1982), lot 386.

The studies of Esty, Equall, and Smith ("The Alloy of the 'XI' Coins of Tacitus," Numismatic Chronicle 1993) and Callu, Brenot, and Barrandon ("Analyses de Séries Atypiques," Quaderni Ticinesi Numismatica e Antichità Classiche 8) suggest that the 'XI' on the coinage of Tacitus signifies a higher silver content than the usual 'XXI' issue of Antoniniani.