Trajan (98-117), Sestertius, Rome, AD 103-111; AE (g 22,28; mm 33; h 7); IMP CAES NERVAE TRAIANO AVG GER DAC P M TR P COS V P P, laureate bust r., drapery on l. shoulder, Rv. S P Q R OPTIMO PRINCIPI, emperor riding r., thrusts spear at Dacian in front of horse; in ex. S C. RIC 543; C 508. Brownish patina, about extremely fine. Restoration and cleaning report by Professor G. Pierbattisti (Conservator Safe Coins s.r.l.): during the analysis of this sestertius, the microscope observation has revealed the artificial deposition of copper nitrate on the surface.Under microscope magnification, was chemically and mechanically operations removed this layer, showing again the original dark patina on both side of the coin.