University of Texas at Austin, has approximated the dating of the cup with similarly styled objects found in Pompeii, due to the lack of archaeological context. Dyfri Williams, previously the Keeper of Greek and Roman Antiquities at the British Museum, dated the cup to AD 5–15. Williams identified several factors supporting that dating. The silver alloy being 95% pure is consistent with other known Roman silver vessels, with silver from later periods having a far higher purity. Cracks in the cup retain chemical corrosion products which are symptomatic of age, remaining despite being cleaned twice during the 20th century. An EDX analysis showed that the corrosion was silver chloride. Subsequent testing in 2015 of the inside repoussé shelf and the reverse of the liner, neither of which had been cleaned, found substantial silver chloride corrosion. The decorative style and shape have a close parallel with many other vessels of the period, such as the Chryses kantharos and the closely matching figures of nude men on the Hoby skyphoi, discovered in Lolland in Denmark a decade after the Warren cup was first recorded. In 2008 and 2013, Maria Teresa Marabini Moevs argued on iconographic grounds that the Warren Cup is a modern forgery executed around 1900 to meet the tastes of Edward Perry Warren, the amateur collector who introduced the artifact to the world. Luca Giuliani, a professor of Classical Archaeology at Humboldt University, initially also argued on iconographic grounds that the Warren Cup was likely to be a twentieth-century forgery. However, he subsequently found that evidence of substantial silver chloride corrosion conclusively established the cup's authenticity. Manufacture and condition The Warren Cup is an estimated 95% pure silver with some copper and trace amounts of lead and gold. It was made in five sections: the main bowl, which was hammered thin from inside and subsequently finished off from the outside to produce the figures in relief; a separate plain inner liner bowl of thicker sheet silver with a solid rim, to make the cup easier to use and to clean; a base in solid silver; a cast foot soldered to the base; two handles, now missing. The cup is etched and pitted due to the effect of corrosive cleaning deposits; however, remnants of silver chloride and black silver sulphide survive in crevices. A crack runs from the rim, around the figure of the boy on one side. The base is