Quadrantes chemical compositions

Additional analyses are required before one may reliably conclude that chemical composition correlates with denomination. There are indications that composition correlates with denomination (e.g., the exceptionally high lead contents of mid-second-century B.C. semisses and asses and the low lead contents of quadrantes). However, larger numbers of coins must be chemically analyzed to obtain a thorough understanding of the Roman Republican copper-based coinage. 

Chemical Compositions of Copper-Based Roman Coins. Augustan Quadrantes, ca. 

The density of pure copper is 8.93 g/cm, and the densities of the Claudian quadrantes average about 8.91 0.04 g/cm. None of the coins has any appreciable quantity of voids or internal pores. Die orientations were determined by rotating each coin about its obverse vertical axis. The reverse vertical axis was then found to point in a given direction, which was identified by the equivalent direction of the hour hand of a clock. All of the 84 Claudian quadrantes in the chemical compositional group. 

A.D. 41 group 41 B see the section on chemical compositions) have a die orientation very close to 6 30 (Appendix A). The mean orientation is 6 27 0 22. This means that great care was taken to orient the reverse die with respect to the obverse die during striking. This is in marked contrast to the striking of Augustan quadrantes in 9-4 b.c. (8), where the die orientations clustered about the four orientations, 1 00, 4 00, 7 00, and 10 00 (1 00 and 7 00 predominate). 

The presently accepted chronology of Augustan quadrantes is probably wrong. Both chemical analyses and size measurements indicate that the 8 B.c. quadrantes are likely to be older than the 9 b.c. quadrantes. Also some Augustan asses have been dated to 7 and 6 b.c., but their compositions are different from those of the quadrantes. It is concluded that the quadrantes, now tentatively dated at 9,8,5, and 4 b.c., were made in a 4-6 yr period during which no asses were minted (8). 

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