Ninety-nine Claudian quadrantes have been analyzed for iron, nickel, copper, silver, tin, antimony, and lead by x-ray fluorescence spectroscopy. The coins are the purest copper of any Romain coins analyzed to date. Fifteen coins were made from small, thick flans; these coins usually contain less nickel but comparatively much more lead, antimony, and silver than do the 84 coins made from normal, thin flans. All the thick-flan coins were struck in AD 41; normal flans were used for coins struck in both AD 41 and 42. Compositions of the quadrantes are very similar to those of Claudian asses (a denomination of larger copper coins) and also to Caligulan quadrantes and asses. However, the compositions are significantly different from Tiberian coins of about AD 34 and Neronian coins of AD 64-66. See also AATA 21-1449 for reference to book.