Chemical Compositions of Copper-Based Roman Coins: Claudian

16

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Chemical Compositions of Copper-Based Roman Coins: Claudian Quadrantes A.D. 41-42 GILES

F.

CARTER

Eastern M i c h i g a n University, C h e m i s t r y Department, Ypsilanti, M I 48197

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 Roman 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 having normal, thin flans. All the thick-flan coins were struck inA.D.41; normal flans were used for coins struck in both A . D . 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 A . D . 34 and Neronian coins of A . D . 64-66.

S

E V E R A L H U N D R E D C O P P E R - B A S E D R O M A N C O I N S have been analyzed by wet chemistry (1-5), x-ray fluorescence spectroscopy (6-11), and atomic

absorption spectroscopy (12). Consequently, a general understanding of the compositions of copper-based Roman coins is developing. F o r i n stance, the debasement of orichalcum (Roman brass) coins by substituting tin and lead for zinc during the late first and second centuries is well

known (1,12). The following three paragraphs contain examples of knowledge gained through determination of the major and trace element compositions of Roman coins: As the first E m p e r o r , Augustus instituted a brilliant new copperbased coinage comprising four denominations: the sestertius and duponThis chapter is the seventh in a series of articles on the chemical composition of copper-based Roman coins. 0065-2393/84/0205-0311$06.00/0 © 1984 American C h e m i c a l Society

Lambert; Archaeological Chemistry—III Advances in Chemistry; American Chemical Society: Washington, DC, 1984.

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ARCHAEOLOGICAL CHEMISTRY


dius, both made of orichalcum, and the as and quadrans, made of nearly pure copper. Furthermore, the major Roman mint at L u g d u n u m (Lyons, France) used essentially the same compositions as d i d that at Rome under Augustus. However, less important mints in the Roman colonies pro duced coins having miscellaneous low concentrations of several percent tin and lead (6). This coinage policy was, indeed, brilliant and is evidence of Augustus' perception of the favorable propaganda value of good quality copper-based coins. So-called imitations, or "military copies," of copper coins of C l a u dius, probably minted in France, Germany, and England for the Roman army, have small, but significant, differences in trace element concen trations from Claudian coins minted in Rome (JO). The presently accepted chronology of Augustan quadrantes is prob ably 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). It is necessary to analyze large numbers of coins to solve most num ismatic problems because of variations in composition within any given period of time and among mints. In fact, the variation itself is important in many instances because it reflects the degree of quality control ex ercised in producing the coin flans at a given time. Obviously, it is not possible to use wet chemical or other destructive techniques to analyze large numbers of coins. Therefore, methods such as neutron activation analysis, x-ray fluorescence, or atomic absorption spectroscopy are fa vored. Atomic absorption spectroscopy, however, requires small samples obtained from drilling into the coin edges. Hence it is usually restricted to large coins. Because x-ray fluorescence analysis determines a rather thin surface layer of metal in coins (see Table I for calculations), the surface must be representative of the entire coin or misleading results are obtained. Carter and Kimiatek (13) compared the compositions of Augustan quadrantes at the surfaces and in the interiors. Usually only small and irregular dif ferences were noted. It was concluded that for nearly pure copper coins, x-ray fluorescence analysis is capable of providing good analyses provided the coins are cleaned properly. Proper cleaning involves removing oxides by electrolytic reduction followed by rubbing with a pencil eraser. T h e n , 10-15 μπι of metal is removed from each surface of the coin by means of an air blast containing fine abrasive particles of chemically pure alu m i n u m oxide ( A 1 0 ) (14). The quadrans was the lowest denomination of Roman coins; slightly worn quadrantes have roughly about the same weight as a U . S . penny, a little over 3 g. Quadrantes, however, are usually smaller in diameter 2

3


16.

CARTER

313

Composition of Copper-Based Roman Coins

Table I. Transmittance of x-Rays by Copper Coins

Surface Thickness of Copper (μτη) Element


Fe Ni Cu Ag Sn(La ) Sb(L ) Pb(Laj) x

a i

J

5

10

15

20

25

0.91 0.94 0.95 0.98 0.62 0.65 0.84

0.63 0.74 0.79 0.88 0.09 0.12 0.42

0.40 0.55 0.62 0.78 0.01 0.014 0.18

0.25 0.41 0.49 0.69 0 0 0.07

0.16 0.31 0.39 0.61 0 0 0.03

0.10 0.23 0.30 0.54 0 0 0.013

30 0.06 0.17 0.24 0.48 0 0 0.006

40 0.02 0.09 0.15 0.37 0 0 0

All values are the transmittance, namely J//. Lead L a x-rays are heavily absorbed by copper because they have moderately higher energy than the absorption edge of copper. NOTE:

0

x

and thicker than a new penny. T h e y were first struck by Augustus i n approximately 9-4 B . C . ; no other quadrantes were struck until the reign of Caligula in the late 30s A . D . A large number of quadrantes was struck by Claudius i n A . D . 41-42. In this chapter we report the results of our analysis of a group of 99 Claudian quadrantes and compare these analyses with those of Augustan quadrantes, Tiberian asses, Caligulan quadrantes and asses, Claudian asses, and Neronian quadrantes and asses.

Experimental Two x-ray fluorescence spectrometers were used for the analyses: a General Electric X R D - 6 for iron, copper, tin, and antimony, and a General Electric X R D - 5 for nickel, silver, and lead (the latter machine has updated electronics and gave superior results for these three elements). Four certified standards from the National Bureau of Standards were used for each element to obtain a straight line calibration curve using linear regression (10). The experimental conditions used for the determination of each element were given by Carter et al. (JO). Each coin was weighed, and its physical dimensions and properties, such as maximum and minimum diameter, maximum thickness, density, and die orientation, were obtained. These results are summarized in Appendix A.

Physical Properties of Claudian Quadrantes T h e density of pure copper is 8.93 g/cm , and the densities of the Claudian 3

quadrantes average about 8.91 ± 0 . 0 4 g/cm . None of the coins has any 3

appreciable quantity of voids or internal pores. D i e orientations were determined by rotating each coin about its obverse vertical axis. T h e reverse vertical axis was then found to point i n a given direction, which was identified by the equivalent direction of the hour hand of a clock. A l l of the 84 Claudian quadrantes in the chemical compositional group,


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A . D . 41 group 41 # B (see the section on chemical compositions) have a die orientation very close to 6:30 (Appendix A). T h e mean orientation is 6:27 ± 0 : 2 2 . 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). F i v e of the 15 coins in the compositional group 41 # A have die orientations close to 12:30. T h e significance of this fact is unknown, although it may indicate that the compositional group 41 # A comprises coins struck in a different workshop, or even possibly that these coins were merely copies of the other Claudian quadrantes. However, there is no other evidence to indicate that quadrantes were copies. Large numbers of copies of Claudian asses (large copper coins about 3 cm in diameter) and dupondii (brass coins about the size of asses) are known. O n the average, coins from group 41 # A are appreciably thicker than quadrantes from group 41 # B . However, this general rule does not apply to every coin. There are a few thick coins in group 41 # B and a few thin coins in group 41 # A . Almost every coin whose very poor condition makes its complete identification impossible belongs to the small group 41 # A . This finding is surprising, and again may indicate that group 41 # A are copies that were poorly struck. A l l groups of coins have roughly the same average ellipticity (maxi m u m diameter divided by the minimum diameter; see Appendix A). The weights of the quadrantes vary considerably and are not representative of weights for all Claudian quadrantes because these coins were dredged from the T i b e r River and subsequently cleaned. Coins in m u seum collections are usually outstanding specimens and have a much higher average weight than the Claudian quadrantes in this study. M u seum coins are on the average at least 0.5 g heavier. T h e weights of quadrantes i n private collections are unknown. Corrosion will change the weight of a coin far more than it will affect the maximum or m i n i m u m diameter or the maximum thickness. Hence the weights of these coins are useful primarily to identify the coins in the future (most are being sold to collectors, but some may enter eventually into museum collections). N o significant differences in size or physical properties could be correlated with catalog numbers of the quadrantes. Figure 1 illustrates the different varieties of Claudian quadrantes, namely B M C [British M u s e u m Catalog number (15)] 174, 179, 181, 182, and 182 variety.

Chemical Compositions of Claudian Quadrantes Ninety-nine Claudian quadrantes made in A . D . 41 or 42 were analyzed for several elements (approximate standard deviations are in parenthe-


CARTER



16.

Figure 1. Claudian quadrantes: magnification is 2 X ; BMC, British Mu seum Catalog (15). Coin no. 1164 is the only coin from compositional group 41 ΦΑ. All other coins are from group 41 #B. BMC 182 variety is the same as BMC 182 except "FF" is omitted from its reverse legend. Continued on next page. Lambert; Archaeological Chemistry—III Advances in Chemistry; American Chemical Society: Washington, DC, 1984.



316

Figure 1—continued. Claudian quadrantes: magnification is 2 X ; BMC, British Museum Catalog (15). Coin no. 1164 is the only coin from com positional group 41 ΦΑ. All other coins are from group 41 #B. BMC 182 variety is the same as BMC 182 except "FF" is omitted from its reverse legend.


16.

CARTER

Composition of Copper-Based

Roman Coins

317

ses): iron (0.003%), nickel (0.003%), silver (0.007%), tin (0.003%), antimony (0.003%), and lead (0.02%) (Appendix B). Sixty-one quadrantes were produced i n A . D . 41, 31 i n A . D . 42; 7 are of unknown date. In A . D . 41 there were apparently two groups of quadrantes: 15 quadrantes appear to belong to one compositional group, called group 41 # A , and these coins tend to have relatively low concentrations of iron and nickel as well


as high concentrations of silver, antimony, and sometimes lead: 0 . 0 8 6 ± 0 . 0 4 3 % F e (thick flans) vs. 0.141 ± 0 . 0 6 4 % F e (thin flans); 0.008 ± 0 . 0 0 5 % N i (thick flans) vs. 0.015 ± 0 . 0 0 5 % N i (thin flans); 0 . 0 2 9 ± 0 . 0 1 4 % A g (thick flans) vs. 0 . 0 0 4 ± 0 . 0 0 3 % A g (thin flans); 0.049 ± 0 . 0 1 6 % Sb (thick flans) vs. 0.009 ± 0 . 0 0 4 % Sb (thin flans); 0.11 ± 0 . 0 6 % P b (thick flans) vs. 0 . 0 4 ± 0 . 0 2 % P b (thin flans). These quadrantes almost always are smaller and thicker than those i n the other group (see Appendix A), and occasionally the size of the letters in the inscription is significantly smaller than it is i n the second group. T h e second compositional group comprises 84 quadrantes, and it is called group 41 # B . Compositions of the group 41 # B quadrantes made i n A . D . 41 are experimentally indistinguishable from the compositions of A . D . 42 quadrantes, all of which also belong to the compositional group 41 # B (Appendix B). This observation leads one to believe that the group 41 # B coins were struck continuously from A . D . 41 into A . D . 42. Compositional group 41 # B is characterized by moderate iron and nickel concentrations compared with other Roman coins of nearly pure copper. Also, their copper concentrations are comparatively h i g h — i n fact, they are the highest known for any group of Roman coins. T h e silver, tin, antimony, and lead concentrations of this compositional group are the lowest known for any group of Roman copper-based coins. C o i n no. 1159 has an unusually high tin, as well as antimony and lead, content. This coin is the only one having a composition quite different from those of either group 41 # A or 41 # B .

Comparison of Compositions with Those of Other Roman Coins of About the Same Age Table II summarizes previous analyses and compares them with the present two compositional groups 41 # A and 41 # B (the quadrantes made i n A . D . 42 all belong to the compositional group 41 #B). Nine Claudian asses, which are large-diameter coins of nearly pure copper, have been analyzed (9), and the analyses are very close to the compositions of the group 41 # B coins. F o u r of the asses were minted i n A . D . 41, and five i n A . D . 42.



As and Quadrans As

Caligula

6

37-41

64-66

4

31

52

41

42

15

41

9

14

34-37

41-42

86

4 B.C.

Date, Number A.D. Coins m s m s m s m s m s m s m s m s e

e

fe

0.194 0.137 0.129 0.06 0.087 0.071 0.085 0.045 0.098* 0.062 0.148 0.074 0.166 0.101 0.146 0.080

Fe

Ni 0.010 0.005 0.007 0.006 0.020 0.011 0.017 0.010 0.008 0.005 0.017 0.005 0.012 0.004 0.008 0.004

Cu

fo

e

6

99.5 0.2 99.6 0.18 99.8 0.1 99.9° 0.1 99.6 0.2 99.8 0.1 99.8 0.1 99.2 0.3 0.002 0.005

— — — — — —

a

0.005 0.012 0 0

— — — —

Zn 0.038 0.015 0.068 0.017 0.022 0.029 0.007 0.005 0.029 0.014 0.004 0.003 0.004 0.003 0.092 0.017

Ag 0.016 0.043 0.012 0.009 0.012 0.013 0.006 0.004 0.018* 0.042 0.004 0.002 0.005 0.002 0.019 0.010

Sn

0.084 0.042 0.076 0.038 0,016 0.016 0.009 0.003 0.054* 0.023 0.009 0.004 0.008 0.003 0.089 0.037

Sb

0.17 0.07 0.075 0.04 0.02 0.02 0.01 0.02 0.15* 0.16 0.04 0.02 0.04 0.02 0.49 0.21

Pb

c

0

NOTE: m, mean; s, standard deviation. One coin contained 0.58% iron and 0.22% zinc and was omitted from the group in calculating m and s for iron, copper, and zinc. * Omits one outlying determination. Omits outlyers.

Nero

Claudius

Claudius

Claudius

Quadrans (group* 41 #A) Quadrans (group 41 #B) Quadrans (group 41 #B) As

As

Tiberius

Claudius

Quadrans

Denomination

Augustus

Emperor

Table II. Comparison of Compositions of Claudian Quadrantes with Compositions of Tiberian, Caligulan, and Neronian Coins


16.

CARTER


319

Seven previously analyzed Claudian quadrantes (9) are fairly close in composition to the ones reported in this chapter. However, improved analytical techniques and use of a better x-ray fluorescence spectrometer for nickel, silver, and lead analyses have produced results that are prob ably more accurate than the previous ones. T h e Claudian quadrantes group 41 # A (thick flans) have nearly the


same composition as the imitation Claudian asses. T h e primary difference is in silver concentration, but the difference is large enough to indicate that there is probably no connection between Claudian imitation asses and group 41 # A quadrantes. Augustan quadrantes, attributed to 9-4 B.c., have compositions sim ilar only to the group 41 # A coins (see Table II). T h e y are quite different from the large group 41 # B . However, usually the group 41 # A Claudian quadrantes have less iron, more copper, and less silver, antimony, and lead than Augustan quadrantes. It is possible, but not too probable, that Augustan quadrantes were restruck as Claudian quadrantes group 41 # A . A n alternate possibility is that Augustan quadrantes or asses were melted along with some new copper to produce the Claudian 41

#A

quadrantes. T h e Caligulan asses and quadrantes (six analyses) of A . D . 37-41

have

nearly the same composition as Claudian quadrantes group 41 # B (Table II). This finding would indicate that the group 41 # A quadrantes either were copies or were produced at a separate workshop, because apparently Caligulan coins and Claudian quadrantes

and asses were

produced

throughout A . D . 41 and into A . D . 42, all with about the same compositions, namely those of group 41 # B . Fourteen Tiberian asses dating from A . D . 34-37 have been analyzed (9). These coins are different in trace element composition from either group 41 # A or 41 # B (Table II). F o r instance, the Tiberian asses have significantly higher silver contents and usually more antimony and less lead than group 41 # A coins. T h e Tiberian asses are quite different from the group 41 # B Claudian quadrantes. Neronian asses were produced in A . D . 64-66, long after the Claudian quadrantes, but essentially no copper-based Roman coins were produced in the interim period, A . D . 4 3 - 6 3 . It is, therefore, of interest to compare the trace element compositions of nearly pure copper coins of Claudius and Nero to determine whether significant changes occurred, indicating different ore sources or conditions of smelting and refining. Indeed, there are significant differences: T h e silver contents of the Neronian asses are very high, namely 0.092 ± 0.017%, versus 0.029 ± 0.014% i n the group 41 φ A Claudian quadrantes. (However, only four Neronian coins minted in Rome have been analyzed.) Also, the antimony and lead contents of the Neronian asses are significantly higher in most of the coins (Table II). C o p p e r ores and(or) conditions of smelting and refining were different for the Neronian asses. Perhaps the catastrophic great fire in Rome just


320

ARCHAEOLOGICAL

CHEMISTRY

prior to the striking of Nero's copper coins meant that the new copper was prepared in great haste and was not desilvered by using liquid lead.

Numismatic Questions


The chemical analyses and physical properties of Claudian quadrantes raise several questions for future study: 1. W h y are there two major compositional groupings of C l a u dian quadrantes? 2. Is the compositional group 41 # A different because the coins are copies or because they were made in a separate workshop? 3. W h y are the issues of B M C 181 and B M C 182 variety so small in numbers of coins? Is B M C 181 merely a hybrid coin made from an obverse die produced in A . D . 41 and a reverse die from A . D . 42? Is B M C 182 variety simply an engravers mistake in omitting " P P " from the reverse legend (see Figure 1)? 4. W h y is there more than one issue per year? 5. W h y are all the thick-flan group 41 # A coins limited to A . D . 41? (Why were not some made in A . D . 42?) 6. W e r e the A . D . 42 coins minted for only part of the year?

Conclusion There are two broad compositional groups of Claudian quadrantes. C l a u dian asses have compositions essentially the same as those of the larger of these groups. Also, Caligulan quadrantes and asses are very similar to this compositional group, but additional Caligulan copper coins must be analyzed to enable an investigator to tell whether these coins represent a different compositional group. Tiberian and Neronian copper coins are significantly different in trace element compositions from the Claudian quadrantes. T h e large number of Claudian quadrantes analyzed has provided ample evidence for two rather close-knit compositional groups. It is to be hoped that numismatists will be able to deduce reasons for the existence of the relatively small compositional group 41 # A , which has smaller and thicker flans than the other group, group 41 # B . Because group 41 # B coins have a higher purity than other Roman coins, they were probably made from virgin copper.

Acknowledgments I am grateful to the Kelsey-Hayes Research and Development Laboratory in A n n Arbor, M i c h . , and to the Lewis Research Center of N A S A in Cleveland for the use of their x-ray fluorescence spectrometers. A p preciation is also given to Simon Bendall and to A . H . Baldwin & Sons L t d . in L o n d o n for supplying the coins for analysis.


Maximum Thickness (cm)

Lambert; Archaeological Chemistry—III Advances in Chemistry; American Chemical Society: Washington, DC, 1984. 1.069 1.052 1.193 1.073 1.048 1.102 1.090 0.054 6:00 8:00 12:30 6:30 1:00 1:00? 8.93 8.85 8.91 8.88 8.82 8.85 8.87 0.04 8.90 0.03

0.309 0.266 0.259 0.255 0.241 0.186 0.253 0.040 0.229 0.047

1.348 1.435 1.289 1.346 1.426 1.487 1.388 0.073 1.512 0.129

1.441 1.510 1.538 1.444 1.494 1.639 1.511 0.073 1.633 0.129

3.1692 2.5800 2.6525 2.7095 2.4521 1.8252 m 2.565 s 0.437

m 2.626 s 0.490

174 or 179 174 or 179 174 or 179 174 or 179 174 or 179 174 or 179

1097 1148 1152 1159 1163 1169

Footnotes are at end of table.

Continued on next page.

1.082 0.037

1.047 1.076 1.058 1.100 1.070 0.023 5:30 6:30 6:00 5:30 5:52 0:29 8.93 8.90 8.91 8.92 8.92 0.01

0.235 0.167 0.182 0.243 0.207 0.038

1.530 1.642 1.725 1.625 1.630 0.080

1.602 1.767 1.825 1.787 1.745 0.098

2.8675 2.0448 2.6115 2.7885 m 2.578 s 0.371

179 179 179 179

1094 1127 1132 1189

For all of group 41#A

1.083 1.060 1.095 1.106 1.064 1.082 0.020 11:30 6:30 7:00 7:30 1:00

8.95 8.90 8.88 8.90 8.91 8.91 0.03

0.257 0.206 0.150 0.293 0.185 0.218 0.057

1.522 1.654 1.614 1.449 1.582 1.564 0.080

Die Orientation

1.649 1.753 1.767 1.602 1.684 1.691 0.070

3

Density (g/cm )

Ratio of Maximum to Minimum Diameter

3.4145 2.4916 1.8130 3.4335 2.5328 m 2.737 s 0.689

A.D.41 Group 41 # A

Minimum Diameter (cm)

174 174 174 174 174?

Catalog Number

Maximum Diameter (cm) Weight (g)

Dimensions and Physical Properties of Claudian Quadrantes

1117 1120 1146 1164 1190

Coin Number

Appendix A


rt*\ j Ο

3

h-"

to

GO

Ce

ο S"

£» ο

1

Ο ο

o"

posi

Lambert; Archaeological Chemistry—III Advances in Chemistry; American Chemical Society: Washington, DC, 1984. 1.672 1.603 1.688 0.152

1.5771 1.8863 m 2.148 s 0.521

174 174

1188 1192

1.597 1.503 1.598 0.062

1.769 1.583 1.616 1.528 1.602

1.866 1.691 1.715 1.642 1.690

2.5781 1.9297 1.5517 2.2696 1.6139

174 174 174 174 174

1177 1179 1183 1185 1187

1.519 1.549 1.621 1.532 1.617

1.760 1.639 1.786 1.604 1.957

174 174 174 174 174

1157 1161 1167 1171 1175

1.9598 1.7860 2.1169 1.9928 1.5368

2.6968 0.8457 2.4590 3.2274 2.4342

174 174 174 174 174

1133 1136 1142 1150 1154

1.627 1.543 1.705 1.571 1.585

1.707 1.647 1.842 1.775 1.649 1.565 1.571 1.629 1.613 1.568

2.2600 2.9115 2.7566 2.0076 2.1328

174 174 174 174 174

1113 1123 1125 1128 1130

1.597 1.648 1.690 1.524 1.671

1.640 1.695 1.750 1.708 1.749

1.601 1.591 1.775 1.746 1.647

2.2160 1.8077 3.0063 2.1016 2.3239

174 174 174 174 174

1095 1099 1104 1107 1110

(cm)

8.90 8.91 8.92 0.04

8.90 8.79 8.92 8.91 8.92

0.181 0.178 0.133 0.180 0.136 0.146 0.162 0.171 0.030

8.93 8.92 8.88 8.93 8.91

8.92 9.04 8.89 8.91 8.91

0.205 0.098 0.210 0.223 0.194 0.183 0.150 0.167 0.168 0.119

8.97 8.90 8.94 8.94 8.94

8.93 8.94 8.92 8.96 8.88

6:30 6:30 6:28 0:22

7:00 6:30 6:00 6:30 6:00

6:30 6:00 7:00 7:00? 6:30

6:30 6:00 7:00 6:00 7:00

6:30 7:00 6:30 6:00 6:30

6:30 6:00 6:30 6:00 6:30

Die Orientation

(g/cm ) 3

Density

0.173 0.226 0.183 0.152 0.182

0.173 0.139 0.204 0.170 0.170

A . D . 41 G r o u p 41 # B

(cm)

(cm)

Thickness

Diameter

Diameter

Weight (g)

Catalog

Number

Coin

Number

iMaximum

Minimum

Maximum

Dimensions and Physical Properties of Claudian Quadrantes—Continued


Ratio of

1.047 1.067 1.070 0.044

1.055 1.068 1.061 1.075 1.055

1.159 1.058 1.102 1.047 1.210

1.023 1.013 1.090 1.082 1.050

1.049 1.067 1.080 1.130 1.040

1.027 1.029 1.036 1.121 1.047

Diameter

Minimum

Maximum to

Lambert; Archaeological Chemistry—III Advances in Chemistry; American Chemical Society: Washington, DC, 1984. 7:00 6:00 6:00 6:00 6:30 6:24 0:21

8.90 8.85 8.89 8.88 8.93 8.90 0.04 0.201 0.200 0.224 0.113 0.174 0.194 0.030

1.541 1.599 1.650 1.693 1.600 1.634 0.069


1.816 1.817 1.709 1.880 1.680 1.776 0.100

2.1549 2.2208 2.8131 1.3862 1.9254 m 2.467 s 0.477

179 179 179 179 179

1174 1178 1182 1186 1191


1.178 1.136 1.036 1.110 1.050 1.087 0.051

1.125 1.084 1.225 1.059 1.097

6:00 6:30 6:30 6:30 6:30

8.91 8.91 8.89 8.89 8.92

0.181 0.224 0.190 0.214 0.233

1.604 1.618 1.646 1.657 1.577

1.804 1.754 2.017 1.755 1.730

2.6029 2.8025 2.4835 3.0431 2.7243

179 179 179 179 179

1153 1156 1160 1166 1170

1.031 1.052 1.081 1.094 1.049

6:30 6:30 6:30 7:00 6:30

8.93 8.93 8.91 8.91 8.91

0.213 0.167 0.199 0.197 0.168

1.622 1.734 1.556 1.645 1.601

1.673 1.825 1.682 1.799 1.679

2.8678 2.4843 2.5423 2.3433 1.8117

179 179 179 179 179

1135 1137 1141 1145 1149

1.056 1.040 1.080 1.034 1.045

6:00 6:00 6:30 6:00 7:00

0.190 0.194 0.149 0.237 0.177

1.786 1.666 1.682 1.622 1.725

1.886 1.733 1.817 1.677 1.803

3.1233 2.5955 1.7832 3.1871 2.1617

179 179 179 179 179

1116 1119 1122 1124 1129

8.94 8.86 8.79 8.95 8.93

α

1.109 1.187 1.073 1.055 1.091

8.93 8.89 8.90 8.80 8.95

0.191 0.153 0.226 0.183 0.242

1.563 1.668 1.753 1.532 1.520

1.733 1.980 1.881 1.617 1.659

2.5338 1.9460 2.9630 2.0843 3.0947

179 179 179 179 179

1098 1103 1106 1109 1112

6:30 7:00 6:00 6:00 6:30

A . D . 41 Group 41 #B


S3

03

δ"

Ο ο

3

Ο

(ft ?»

CO

Ο ο "β •β

ο ο

I

Ο ο

Ά

>

Ω


Catalog

Number

181 182 182 182 182 182

182 182 182 182 182

182 182 182 182 182 182

182 182 182 182

182 182 182 182 182

182

Coin

Number

1143 1096 1100 1105 1108 1111

1114 1118 1121 1126 1131

1134 1138 1139 1140 1144 1147

1151 1158 1162 1165

1168 1172 1173 1176 1180

1184

1.7698 m 2.225 s 0.457

2.5599 2.1088 2.4085 1.9164 2.2939

2.2606 2.7232 2.5054 1.2066

1.5558 2.4626 1.8708 2.0763 2.4612 2.9402

2.2810 1.9348 1.9627 2.5469 1.4397

1.9059 2.8243 3.0966 2.4785 3.1234 2.6194

Weight (g)

1.670 1.730 0.070

1.763 1.688 1.659 1.706 1.810

1.699 1.736 1.721 1.613

1.807 1.784 1.736 1.702 1.833 1.727

1.807 1.652 1.662 1.720 1.600

1.666 1.790 1.776 1.783 1.721 1.868

(cm) (cm)

Diameter

Minimum (cm)

Thickness

Maximum

1.578 1.609 0.060

1.632 1.519 1.611 1.581 1.592

1.605 1.698 1.536 1.481

1.618 1.648 1.643 1.638 1.715 1.566

1.728 1.580 1.580 1.613 1.544

1.549 1.576 1.643 1.681 1.593 1.634

0.175 0.180 0.020

0.195 0.178 0.179 0.161 0.176

0.179 0.172 0.206 0.148

0.158 0.196 0.154 0.176 0.176 0.221

0.161 0.175 0.176 0.193 0.156

0.155 0.216 0.221 0.209 0.230 0.185

A.D. 42 Group 41 # B

Diameter

Maximum

8.93 8.92 0.02

8.92 8.87 8.91 8.91 8.91

8.93 8.91 8.91 8.91

8.96 8.88 8.93 8.91 8.89 8.90

8.96 8.95 8.95 8.92 8.96

8.94 8.93 8.94 8.93 8.93 8.94

3

(g/cm )

Density

6:30 6:32 0:23

7:00 6:30 6:00 6:30 6:30

6:00 6:30 6:30 6:30

6:30 6:30 6:30 7:30 7:00 6:30

7:00 7:00 6:30 7:00 6:00

6:30 6:00 6:00 6:30 6:00 6:30

Orientation

Die

Dimensions and Physical Properties of Claudian Quadrantes—Continued


Ratio of

1.058 1.076 0.035

1.080 1.111 1.030 1.079 1.137

1.059 1.022 1.120 1.089

1.117 1.083 1.057 1.039 1.069 1.103

1.046 1.046 1.052 1.066 1.036

1.076 1.136 1.081 1.061 1.080 1.143

Diameter

Minimum

Maximum to


? ?

182 var. 182 var. 182 var.

2.5785 2.5032

2.6314 1.6258 2.3104 m 2.189 s 0.514 1.726 1.710

1.706 1.724 1.623 1.684 0.054 1.596 1.618

1.621 1.593 1.553 1.589 0.034 0.212 0.185

0.200 0.143 0.182 0.175 0.029 8.95 8.90

8.93 8.94 8.91 8.93 0.02 6:00 6:30

6:30 6:00 6:30 6:20 0:17

a

Rough surface on this coin; air bubble could cause a slightly low result.

NOTE: m, Mean; s, standard deviation; catalog number, British Museum Catalog number (15); var., variety.

1115 1181

1101 1102 1155


1.081 1.057

1.052 1.082 1.045 1.060 0.020

is

s*

ça Ο ο

1

a!»

00

ta

CIS

*e

"β

Ο ο

g

§

H 5d

M

326


Appendix Β Chemical Compositions of Claudian Quadrantes

Coin Number

Catalog Number

Fe

Ni

Cu

Ag

Sn

Sb

Pb

0.042 0.015 Ν 0.034 0.035 0.025 0.017

0. 008 0. 007 0. 014 0. 003 0. 007 0. 008 0. 004

0. 067 0. 031 0. 019 0. 036 0. 064 0. 043 0. 021

0. 13 0. 07 0. 28 0. 04 0. 15 0. 13 0. 09


A . D . 41 Group # A 1117 1120 1146 1164 1190

174 174 174 174 174?

0. 154 0. 064 0. 071 0. 168 0. 438° m 0. 114 s 0. 054

0. 001 0. 003 0. 014 0. 007 0. 004 0. 006 0. 005

99.6 99.8 99.6 99.7 99.3 99.7 0.1

1094 1127 1132 1189

179 179 179 179

0. 132 0. 048 0. 065 0. 102 m 0. 087 s 0. 038

0. 020 0. 011 0. 007 0. 007 0. 011 0. 006

99.7 99.8 99.7 99.7 99.7 0.05

0.016 0.015 0.038 0.021 0.022 0.011

0. 005 0. 003 0. 006 0. 006 0. 005 0. 001

0. 050 0. 048 0. 070 0. 058 0. 056 0. 010

0. 10 0. 08 0. 16 0. 12 0. 12 0. 03

1097 1148 1152 1159 1163 1169

174 or 174 or 174 or 174 or 174 or 174 or

0. 008 0. 011 0. 005 0. 014 0. 003 0. 002 0. 007 0. 005

99.5 99.8 99.8 98.9 99.8 99.7 99.8 0.05

0.037 0.040 0.041 0.024 0.034 0.049 0.038 0.008

0. 013 0. 007 0. 008 0. 170 0. 013 0. 006 0. 009 0. 003

0. 047 0. 060 0. 036 0. 116 0. 067 0. 037 0. 049 0. 014

0.,12 0. 07 0. 11 0. 69 0. 06 0..08 0. 09 0.,03

0. 008 0. 005

99.7 0.029 0.08 0.014

0. 008 0. 003

0. 049 0. 016

0.,11 0.,06

179 179 179 179 179 179?

All of group 41 #A

0. 259 0. 037 0. 043 0. 088 0. 051 0. 094 m 0. 063 s 0. 026

e

m 0. 086 s 0. 043

e

e

e

e

e

e

A . D . 41 Group 41 # B 1095 1099 1104 1107 1110

174 174 174 174 174

0. 188 0. 095 0. 155 0. 199 0. 230

0. 019 0. 018 0. 016 0. 019 0. 018

99.7 99.8 99.8 99.7 99.7

0.011 0.008 0.007 0.002 Ν

0. 002 0. 006 0.,007 0.,002 0.,005

0. 004 0. 010 0. 020 0. 011 0. 011

0,,03 0.,04 0,,03 0,,04 0,,04

1113 1123 1125 1128 1130

174 174 174 174 174

0. 191 0. 074 0.,142 0.,194 0.,082

0.,018 0. 014 0.,017 0.,021 0.,018

99.8 99.8 99.8 99.7 99.9

0.014 0.009 0.005 Ν 0.003

Ν 0,,001 0,,002 0,,003 0,,002

0,,008 0.,021 0.,009 0,,005 0,,002

0,,02 0,,04 0,,02 0,,03 0,,03

1133 1136 1142 1150 1154

174 174 174 174 174

0,,782 0.,069 0.,082 0.,132 0.,160

0.,016 0.,010 0,,019 0.,013 0,,013

99.1 99.8 99.8 99.8 99.8

0.006 0.009 Ν Ν Ν

0,,006 0,.005 0,.005 0,.003 0 .004

0,,007 0.,024 0,,009 0,,011 0,,005

0,,07 0,.03 0,.06 0,.06 0 .02

1157 1161 1167 1171 1175

174 174 174 174 174

0. 207 0. 207 0. 061 0. 168 0. 210

0. 022 0. 014 0.,021 0.,029 0.,021

99.7 99.7 99.9 99.8 99.7

Ν 0.002 0.004 0.008 0.003

Ν 0,,001 0,,005 0,,003 0.,003

0. 009 0. 009 0.,008 0.,009 0,,014

0.,03 0,,03 0,,03 0,,02 0,,06

e

e



CARTER

16.

Chemical Compositions of Claudian Coin Number

327


Catalog Number

Fe

Ni

Quadrantes—Continued Cu

Ag

Sn

Sb

Pb


A . D . 41 Group 41 #B—Continued 1177 1179 1183 1185 1187

174 174 174 174 174

0.084 0.081 0.228 0.231 0.186

0.003 0.018 0.030 0.014 0.012

99.8 99.8 99.7 99.7 99.8

0.004 Ν 0.006 Ν Ν

0.001 0.004 0.002 0.002 0.005

0.011 0.003 0.017 0.011 0.004

0.05 0.05 0.06 0.03 0.04

1188 1192

174 174

0.344 0.210 m 0.162 s 0.069

0.020 0.017 0.017 0.005

99.6 99.7 99.8 0.07

0.006 Ν 0.004 0.004

0.006 0.003 0.003 0.002

0.011 0.006 0.011 0.008

0.04 0.06 0.04 0.015

A . D . 41 Group 41 #B 1098 1103 1106 1109 1112

179 179 179 179 179

0.121 0.070 0.075 0.053 0.144

0.016 0.010 0.015 0.003 0.023

99.8 99.9 99.8 99.9 99.8

Ν 0.005 0.004 Ν 0.005

0.004 0.001 0.008 0.004 0.004

0.011 0,009 0.006 0.008 0.009

0.05 0.03 0.05 0.03 0.02

1116 1119 1122 1124 1129

179 179 179 179 179

0.173 0.054 0.627 0.090 0.064

0.020 0.014 0.021 0.010 0.020

99.8 99.9 99.3 99.9 99.9

Ν 0.002 0.005 0.004 0.005

0.004 0.008 0.004 0.002 0.001

0.009 0.016 0.015 0.012 0.006

0.04 0.04 0.05 0.02 0.03

1135 1137 1141 1145 1149

179 179 179 179 179

0.292 0.377 0.080 0.156 0.150

0.019 0.019 0.020 0.015 0.020

99.6 99.5 99.8 99.8 99.8

0.004 Ν 0.008 Ν 0.002

0.007 0.005 0.006 0.002 0.004

0.007 0.011 0.006 0.011 0.006

0.05 0.06 0.08 0.04 0.02

1153 1156 1160 1166 1170

179 179 179 179 179

0.177 0.130 0.083 0.119 0.245

0.020 0.017 0.006 0.017 0.015

99.7 99.8 99.9 99.8 99.7

0.008 Ν 0.006 0.004 0.004

0.005 0.002 Ν 0.006 0.004

0.008 0.009 0.006 0.007 0.011

0.05 Ν Ν Ν 0.03

1174 1178 1182 1186 1191

179 179 179 179 179

0.120 0.085 0.101 0.118 0.125 m 0.123 s 0.059

0.013 0.010 0.014 0.020 0.016 0.016 0.005

99.8 99.9 99.8 99.8 99.8 99.8 0.08

0.003 0.001 0.007 0.001 Ν 0.003 0.003

0.006 0.008 0.004 0.003 0.002 0.004 0.002

0.008 0.008 0.009 0.008 0.006 0.009 0 003

0.02 0.03 0.05 0.02 0.02 0.03 0.02

1143

181

0.006

0.008

0 009

Ν

0.002 0.006 0.001 Ν 0.009

0.005 0.005 0.003 0.006 0.007

0.008 0.012 0.013 0.004 0.011

002 0.05 0.02 0.01 0.03

e

e

e

e

A . D . 42 Group 41 #B 0.143

0.013

99.8

A . D . 42 Group #B 1096 1100 1105 1108 1111

182 182 182 182 182


0.149 0.113 0.118 0.251 0.390°

0.009 0.006 0.011 0.016 0.010

99.8 99.8 99.8 99.7 99.5°



328


Chemical Compositions of Claudian Quadrantes—Continued

Coin Number

Catalog Number


A.D.

Fe

Ni

Cu

Ag

Sn

Sb

Pb

42 Group #B—Continued

1114

182

0.122

0.007

99.8

0.004

0.003

0.007

0.01

1118

182

0.346°

0.012

99.6°

Ν

0.006

0.008

0.06

1121

182

0.094

0.010

99.8

0.010

0.003

0.020

0.06

1126

182

0.198

0.011

99.7

0.003

0.006

0.007

0.03

1131

182

0.157

0.009

99.8

Ν

0.004

0.006

0.02

1134

182

0.104

0.019

99.9

0.002

0.005

0.007

0.01

1138

182

0.066

0.011

99.9

0.003

0.005

0.011

0.03

1139

182

0.168

0.013

99.8

0.007

0.003

0.008

0.01

1140

182

0.087

0.010

99.8

Ν

0.005

0.008

0.04

1144

182

0.085

0.013

99.9

0.005

0.003

0.005

0.02

1147

182

0.089

0.004

99.9

Ν

Ν

0.005

0.05

1151

182

0.093

0.010

99.9

0.008

0.007

0.008

0.01

1158

182

0.150

0.014

99.8

0.007

0.008

0.008

0.06

1162

182

0.335°

0.016

99.6°

0.006

0.009

0.007

0.05

1165

182

0.226

0.016

99.6

0.007

0.005

0.008

0.11

1168

182

0.136

0.005

99.8

0.002

0.004

0.002

0.04

1172

182

0.048

0.008

99.9

0.008

0.002

0.004

0.04

1173

182

0.179

0.009

99.8

Ν

0.008

0.009

0.03

1176

182

0.134

0.023

99.8

Ν

0.005

0.008

0.05

1180

182

0.138

0.009

99.8

0.006

0.005

0.012

0.04

1184

182

0.439°

0.012

99.5°

0.002

0.008

0.009

0.06

m 0.135

0.012

99.8

0.004

0.005

0.008

0.04

s

0.004

0.08

0.003

0.002

0.004

0.02

0.02

0.052

A.D. var. 182 var. 182 var.

1101

182

1102 1155

42 Group 41

#B

0.089

0.019

99.8

0.003

0.007

0.008

0.106

0.016

99.8

0.007

0.004

0.006

0.03

0.323

0.016

99.6

0.005

0.008

0.008

0.08

0.017

99.7

0.005

0.006

0.007

0.04

0.002

0.002

0.001

0.03

m 0.173 s 0.130

0.002

0.12

1115

?

0.127

0.011

99.8

0.005

0.002

0.008

0.03

1181

?

0.119

0.010

99.8

0.006

0.003

0.010

0.04

All of group 41 #B

m

0.141

0.015

99.8

0.004

0.004

0.009

0.04

s

0.064

0.005

0.08

0.003

0.002

0.004

0.02

(82 coins) N O T E : All determinations are weight percent, m, Mean; s, standard deviation; catalog number, British Museum Catalog number (15); var., variety; N , none detected. a

Outlying result is omitted from calculation of the mean and standard deviation.


16.

CARTER


329


Literature Cited 1. Caley, E . R. "Orichalcum and Related Ancient Alloys"; Numismatic Notes and Monographs No. 151; American Numismatic Society: New York, 1964. 2. Caley, E . R. "Analysis of Ancient Metals"; Macmillan: New York, 1964. 3. Cope, L . H.; Billingham, H . N . Bull. Hist. Metall. Group 1967, I, 9 1-6. 4. Cope, L . H . Methods Chem. Metall. Invest. Ancient Coinage, Symp., Spec. Publ. R. Numis. Soc. 1972, 8, 49-66. 5. Cope, L . H . Numismatic Chronicle 1968, 7, 115-49. 6. Carter, G . F. In Sci. Archaeol., Symp. Archaeol. Chem., 4th, 1968; MIT Press: Cambridge, Mass., 1971; pp. 114-30. 7. Carter, G . F . ; Buttrey, T. V. Amer. Numis. Soc. Mus. Notes 1977, 22, 4965. 8. Carter, G . F. In "Archaeological Chemistry II", Carter, G . F . , E d . ; A D V A N C E S IN C H E M I S T R Y SERIES No. 171; American Chemical Society: Washington, D . C . , 1978; pp. 347-77. 9. Carter, G . F.; King, C . E . In "Metallurgy in Numismatics I"; R. Numis. Soc.: London, 1980; pp. 157-67. 10. Carter, G . F.; Kimiatek, M . H.; Klupacs, F. J.; Giard, J. B. Rev. Numismatique 1978, 6 (XX) 69-88. 11. Carter, G . F . ; Theodory, E . S. In "Scientific Studies in Numismatics"; Occasional Paper No. 18, Br. Mus. Research Lab.: London, 1980; pp. 65-80. 12. Riederer, J. Jahrbuch Numismatik Geldgeschichte 1974, 24, 73-98. 13. Carter, G . F.; Kimiatek, M . H . Archaeo-Physika 1979, 10, 82-96. 14. Carter, G. F. Archaeometry 1965, 7, 106-13. 15. Mattingly, H . "Coins of the Roman Empire in the British Museum", Vol. 1; Br. Mus.: London, 1923; reprinted 1965. RECEIVED 1983.

for review November 23, 1982.

ACCEPTED

for publication May 9,


Chemical Compositions of Copper-Based Roman Coins: Claudian

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