The idea of ancient peoples about a coin was formed of three elements: high quality metal, definite external look and fixed weight. First, types and weights of coins were started to be studied by numismatists, but the importance of the investigation of the composition of coinage alloy was understood also rather long time ago. By the beginning of the middle of our century, these works became quite numerous.1 Now it is possible to tell, that the evidence for the chemical composition of coin metal should be taken into consideration side by side with the results of traditional numismatic methods: investigation of types, stamps, metrology and so on. In other words, the composition of coinage metal should be introduced in scientific numismatic studies as a new parameter.
For the representativity of such investigations, the mass character of coins is important. In the present work the complex of two non-destructive methods is presented, which allows carrying out the investigation of all coins of interest from big collections, for example, from the collection of the State Hermitage Museum in Saint Petersburg.
Two independent analytical methods: the X-ray fluorescent spectroscopy and the method of measurements of electrical conductivity of coins were included in this complex. The X-ray fluorescent spectroscopy is a method, which proved itself as an effective method for numismatic investigations already long ago, but the method of measurements of electrical conductivity is quite a new one for the investigation of ancient coins metal. This method is based on the well-known fact, that pure gold, silver and copper, that is the main coin metals, are very good electrical conductors, but the presence of even small additions of other metals in the alloy lead to the considerable decrease of conductivity, which could be fixed by a special inductive device.
These methods were include in a complex, because they supplement each other mutually, and in the aggregate they allow to estimate the percentage of the main component of the alloy: gold, copper, lead, zinc and approximately, indirectly, tin and silver. We should notice, that we did not pretend to achieve a precise analysis of the chemical composition, but only to semi-quantitative estimation of the main composition of the alloy. This complex is intended first of all for the mass investigation of big museum collections for the forming of a statistically meaningful database. During several months in 1995-1996 more than 13,000 coins from the main collection of the Hermitage from the ancient Greek towns surrounding the Black Sea, from Asia Minor, Northern Africa including Egypt were investigated.
The papers of the Russian scientists Nina Frolova and Mikhail Treister were devoted to the investigation of the Bosporan coinage metal. The present work allows to extend our observations on a bigger number of specimens, and on different kinds of alloy - gold, copper and silver coins.
The initial period of the Bosporan coinage from the middle of the 6th to the 5th centuries B.C. is characterised by the issue of only silver coins, which served the inner market, while electrum coins of the town of Cyzicus served for the foreign trade.
Electrum staters of Cyzicus, which were struck according to the Phocean system, the so-called Cyzicenes, played an important role in the monetary circulation of Asia Minor, the Black Sea littoral and Greece itself from the 6th century B.C. until the wide spreading of gold coins minted by Alexander the Great in the 430s B.C. It is known, that staters of Cyzicus, and their smaller denominations (hectai, hemihectai and mishemihectai) were struck of electrum, that is of alloy of gold and silver.
There is an opinion in the scientific literature, which is based on the results carried out at different times using different technical analyses, that the composition of the alloy of the Cyzicenes is varying very much.
In the present work the results of the analyses of the electrum coins of Cyzicus from the State Hermitage Museum collection (Saint Petersburg), undertaken with help of X-ray fluorescent spectroscopy, are presented. The aim of this work was to consider the results of the analyses and to compare them with the data known from literary sources.
There were two alloys of gold and silver, known to Greeks, so-called white gold (leukos chrysos) and electrum, which were used by them for making coins and jewellery. White gold was a natural mixture, which was obtaining by a direct thermal treatment of the particles of alluvial gold sand. Electrum was an artificial alloy of gold and silver, often with addition of some amount of copper. The first coins were struck in the second half of the 7th century B.C. in Lydia of white gold, obtained from gold sand, which the rivers Pactolos and Hermos in Asian Minor are bringing. Ancient written sources (Plinius of the 1st century A.D. and Isidorus of the 7th century A.D.) report that the composition of the natural white gold is determined by the proportion of gold to silver as 5:1 or 3:1. The results of analytical investigations, which are available from literature, evidence, that the gold content of these coins could fluctuate from 69% to 2%.
The development of the technology of refining alluvial golden sand and revealing an ability to increase the gold content in it probably by the method of cementation, which was later recorded by Diodorus and Strabo, allowed the issuing of coins of an artificial alloy, electrum. The earliest evidence for using electrum of controlled quality is found in the inscription about the unique Monetary Union between Mytilene and Phocea, which is dated to the beginning of the 4th, or last years of the 5th century B.C.
The Cyzicenes, which served as a international currency in many towns of the Black Sea littoral, occupied a special place among the other electrum coins because of their exceptional popularity in the classical and late classical periods. The supposition was expressed, that the electrum of the Cyzicenes was considered as a metal, not an artificial alloy, and coins struck of it were circulating according to some fixed value, which were independent of their gold content.
The results of the investigation of the composition of the alloy, obtained for the Cyzicenes from the State Hermitage, are presented in the Supplement, where they have been grouped according to the chronological scheme of H. von Fritze, with dates of the groups according to A. Brett. To retrace the changing of the composition of the alloy in time, the average values and standard deviations were calculated for each of the four periods (see Table 1).
Table 1. Average percentage of the composition of the electrum of Cyzicenes from the collection of the State Hermitage Museum
Number of specimens
Average percentage composition
I (600-500 B.C.)
60.8 ± 1.5
32 ± 1.5
5 ± 3
II (500-460 B.C.)
56.3 ± 3.1
39.6 ± 3.2
3.4 ± 1
III (460-400 B.C.)
53.2 ± 3.5
42.5 ± 3.6
3.7 ± 1
54.2 ± 2.4
41.5 ± 2.6
3.8 ± 0.8
Considering the data represented in Table 1, the conclusion can be made that the content of gold is gradually decreasing a few percent from one period to the next. The average gold content of coins of the periods III and IV are almost similar within the limits of error of measurements. It is necessary to note, that the real gold content in the Cyzicenes could be lower by a few percent, and copper content could be higher, than that measured with the help of X-ray fluorescent spectroscopy, because so-called surface enrichment with precious components of the alloy could have taken place.
Now one could compare the figures in Table 1 and the data, known from the scientific literature. Different methods were applied for the investigation of the composition of the Cyzicenes (see the review in the article of J.F. Healy). This method is good only for two-components alloys. But it is well known, that the Cyzicenes contain several percent of copper besides gold and silver. This fact leads to the result that the gold content measured by SG, is lower and silver content is higher than it is in reality. Indeed, it was confirmed in those rare cases where the same coins were analysed by SG and with help of “wet” chemical analysis. For example, a stater from the collection of the British Museum was investigated first by SG, which gave 51% gold and 49 % silver. Then, the same coin was subjected to chemical analysis, and the result was the following: 57.9% gold, 39 % silver and 3.4 % copper.
Despite of this important note, the data adduced in the articles of K.B. Hofmann and J. Hammer should be taken into account. As these papers were published more than a century ago, it has been necessary to reconsider them according to the typological and chronological scheme of the Cyzicenes, later given by H. von Fritze and H. Gaebler with some additional definition.
If we review the staters and hectai analyzed by J. Hammer together, which is necessary for better statistic significance of the result, then the average gold content for each period is the following:
I period (3 staters analysed) – 44,95 %,
II period (18 staters and 39 hectai) – 44.07 %,
III period (12 staters and 5 hectai) – 42.96 %
IV period (18 staters and 1 hecta) – 36.5 % (see Table 2).
Thus, one could conclude, that the decreasing of the gold content can be observed from the first to the last period of the striking of Cyzicenes.
The smaller collection analysed by K.B. Hofmann gave the following results for the percentage of gold:
I period (1 stater) – 59 %,
II period (4 staters and 4 hectai) – 47.46 %,
III period (1 stater and 1 hecta) – 45.26 %,
IV (2 hectai) – 42.16 % (Table 2).
Thirty coins from the Royal Netherland’s Cabinet at the Hague were investigated by several analytical methods. The amount of gold and silver in the alloy was estimated first with help of specific gravity measurements, and the content of gold, silver and copper was obtained by charged particle and two varieties of neutron activation analyses (NAA): fast and thermal ones. The data of the NAA analysis allow us to introduce corrections to the figures: adjustment of 2% to the gold content and lessening of the silver by 6%. The average corrected data for each period are cited in the Table 2. 3 staters of the I period, 5 staters and 19 hectai of the II period, 3 staters and 1 hecta of the III period and 1 stater of the last, IV period were analysed.
S.A. Bulatovich has listed the results of probe analyses of the staters of the town of Cyzicus from the Orlovka hoard. There were no coins of the first period. The average gold content for the Cyzicenes of the II period is 54.45 %, for the III period – 53.4%, for the most numerous IV period – 53.2 % (see Fig. 1 and Table 2).
Table 2. Summary table on the average gold content in Cyzicenes from the literary sources and data of the authors of the article
Average gold content in Cyzicenes, %
I (600-500 B.C.)
60.8 ± 1.5
II (500-460 B.C.)
56.3 ± 3.1
III (460-400 B.C.)
53.2 ± 3.5
IV (400-330 B.C.)
54.2 ± 2.4
Considering all of these data one could conclude that the gold content in the Cyzicenes gradually decreased from one period to another, and this process could not be accidental, because it is recorded in the data of all known sources. The data of probe analyses given by S.A. Bulatovich, and our data should be reduced on some two percent, because of the possible surface enrichment with precious metals (see note 12 above). One could calculate an average amount of gold content for each period for last three columns of the Table 2. These data appears to be equal to 57 % for the I period, 52.6 % for the II period, 49.2 % for the III period and 48.5 % for the IV period. It is possible to use these data for calculating of the value of the Cyzicenes as metal ingots. (We can not include the data of J. Hammer and K.W. Hoffman concerning the calculation of the average figures for the gold content, because they are probably underestimated, and we have no data on the copper content to introduce any corrections).
It is probable, that the Cyzicenes were struck from natural white gold only in the initial stage, because the highest percentage of gold and largest scattering of the data are observed in the first period. Later the gold content was gradually decreased, which could evidence that the Cyzicenes were struck from an artificial alloy, the composition of which was under government control, because otherwise it would not be such an appropriate tendency to decrease the gold content.
The exchange rate of the Cyzicenes was, as far as it is known, changed during the time of their circulation. In Athens during the period 452 – 429/8 B.C. one Cyzicene stater was equal to 27 Athenian drachmae, in 418/7 – 409/8 B.C. it was equal to 25 drachmae, and during the epoch of Alexander the Great one Cyzicene costs only 21 drachmae and 4 obols (as recorded in pseudo-Demosthenes’ speech against Phormion, dated to 327/6 B.C.). The ratio of gold and silver was also changing from time to time. By the middle of 5th century this ratio was 13:1 or 13.3:1; in 440/39-434/33 it was 14:1, then it started to decrease, and by 406 B.C. it was equal to 12:1, and by 398/7 B.C. – to 11:1 /7. In 370/69 B.C. the ratio was somewhat increased up to 13:1, and, at least, in 337 B.C. it was equal to 10:1 or even to 9.5:1.
The opinion exists that Cyzicene staters were relatively overvalued in respect to the value of the metal, of which they were struck. Let us check this hypothesis with help of the average figures for the gold content, which we have calculated for each period, using the data from the last three columns of Table 2 (see above). According to these calculations, for the middle of the 5th century B.C. the gold content in the Cyzicenes was at the average 52.6 %. Besides gold and silver, the coins also contained copper amounting to about 5-6 % and some other metals (ca. 0.5%). If one considers, that the ratio of gold and silver in that period was 13:1, and the weight of the stater was 16 g, then the intrinsic value of the Cyzicenes, expressed in silver, was equal to: 13x16x0.526+16x0.411 = 116 g. Taking into account that the weight of Athenian drachms was equal to 4.36 g, one could obtain the figure of about 26.6 drachmae for the value of one Cyzicene stater, as a metal ingot. This figure almost precisely corresponds to the exchange rate of Cyzicenes for that time (27 drachmae), in other words, Cyzicene staters in Athens were not over-valuated very much in the middle of the 5th century B.C.
It is known from independent sources that at the end of 5th century B.C. the ratio of gold and silver in Athens was equal to 12:1, and value of the Cyzicene in Athens was about 25 drachmae. For this period, according to our observations, the average gold content was about 49.2%. Following the same calculations (1 stater = 12x16x0.492+16x0.443 = 101.45 g of silver), it can be seen that the value of the metal, of which the Cyzicenes consisted, was equal to 23.3 drachmae, which is somewhat lower, but not very much, than the official exchange rate of Cyzicenes in Athens.
In the 4th century B.C. an abundance of gold in the Eastern Mediterranean states led to a decrease of the gold value in respect to silver by up to 10:1 and to a sudden change in the rate of Cyzicenes in Athens: they only cost 21 drachmae and 4 obols for one stater. The average gold content in the Cyzicenes in period IV, calculated from the Table 2, is equal to 48.5%, and the metallic value of one Cyzicene stater was 10x16x0.485+16x0.45=84.8 g of silver, or about 19.44 drachmae for one Cyzicene. Thus, in Athens at the end of 5th and in 4th century the official rate of Cyzicenes was slightly higher, than the value of them as metallic bars, but the difference was not too big, although it was big enough to ensure necessary profit for the mint of the town of Cyzicus. The composition of the electrum of the Cyzicenes was changed correspondingly with the changing of the gold-and-silver ratio and exchange rate of these coins in Athens.
A rather different picture can be observed at the Northern Black Sea littoral, particularly on Bosporos and in Olbia in the third quarter of the 4th century B.C. As it is known, Cyzicenes were especially popular as an international currency. In the 6th century Cyzicenes were used mostly in the towns of the western Black Sea coast. Although there are some findings of Cyzicenes in Olbia and Panticapaion, which are dated to the 6th century B.C., but this fact in itself cannot prove the wide spreading of Cyzicenes there at that time. Indeed, the Cyzicenes had a very long period of circulation in Olbia and Panticapaion, because coins of different chronological groups were often found in the same hoards. One could only suppose based on a number of indirect data, that the Cyzicenes were involved in the monetary circulation in Bosporos already in the 5th, or at the beginning of the 4th century B.C., and only in the 4th century B.C. they acquired a wide circulation on Bosporos. It is interesting that Attic silver did not circulate at Bosporos and at the Northern Black Sea littoral at all. In Olbia Cyzicenes were circulated probably in the 5th – first half of the 4th century B.C. The decree from Anadolu-Kavak provides evidence for the end of the Cyzicenes in Olbia as a financial resource by the third quarter of the 4th century B.C.
There are two extremely important sources for the 4th century B.C., which mention the exchange rate of Cyzicenes in the Northern Black Sea littoral. One is the Olbian decree of Kanob, dated to the third quarter of the 4th century B.C., the other is pseudo-Demosthenes’ speech against Phormion, dated to 327/6 B.C.
From the last document we know that there were two different exchange rates for Cyzicenes. The Athenian one was equal to 21 and 2/3 Attic drachmae for one Cyzicene. The Bosporan rate was much higher: 28 Attic drachmae for one Cyzicene. We have already calculated, that for this period the value of one Cyzicene stater in Athens, where the ratio of gold and silver was 10:1, was about 19.44 Attic drachmae. We also know that the rate of Cyzicenes on the Bosporos was 28 Attic drachmae. One could, then, conclude that the Cyzicenes were either overvalued on the Bosporos, or that the ratio of gold and silver was different on the Bosporos than in Athens at that time.
Let us try to estimate from independent sources the ratio of gold and silver on Bosporos. A.N. Zograf thought, that the Panticapaion stater was equal to the Cyzicene stater. As already mentioned, the Cyzicene stater had its official value of 28 Attic drachmae, therefore, the Panticapaion stater, which had a weight of 9.09 g in the 320s B.C., should also be equal to 28 Attic drachmae. Bosporan staters of this period were struck of very fine metal (no less than 96-98 % gold), which for sure was considered by the ancient people as a pure gold. Thus, the ratio of gold to silver could be obtained from the equation: 9.09xC = 28x4.36, where C is ratio of gold to silver. It turns out, that C is equal to 13.4 implying that gold had a value 13.4 times higher than silver. It is necessary to note that this calculation is based only on the hypothesis of A.N. Zograf concerning the similarity in value of the Cyzicenes and the Panticapaion stater, therefore the calculation could not be a final one. But if we accept the ratio 13.4:1 obtained by this calculation, it means, that the intrinsic value of the Cyzicenes on the Bosporos was 13.4x16x0.485+16x0.45 = 111.2 g of silver, or 25.5 Athenian drachmae. But we know that the rate of the Cyzicenes was 28 drachmae on Bosporos. Thus, consequently, the Cyzicenes seem to be overvalued, and they were to some extent credit money on Bosporos.
The relative value of gold and silver was determined for later periods at the transition from the 4th to the 3rd century B.C. with help of changing ratio between Bosporan gold and silver staters. Golden staters had a weight of 8.51 g, and silver ones, with a head of young Satyr and head of bull, had a weight of 11.61 g. If the exchange rate of gold staters on Bosporos was the same as those known from Delphian inscriptions, that it was equal to 7 or 7.5 silver staters, it implies that 8.51xC = 11.61x7.5, and C = 10.2. Thus, already in the end of the 4th century the ratio of gold and silver was 10.2:1, and accordingly, quite close to the ratio used in other areas of Greek world.
Let us consider the exchange rate of the Cyzicenes in Olbia in the third quarter of the 4th century B.C. According to a new reading of the Olbian money decree, the price of one Cyzicene stater was 8.5 Olbian staters. Keeping in mind that Olbian silver staters weighted 12 g, one could obtain, that Cx16x0.485+16x0.45=8.5х12, and C = 12.2. That means that ratio of gold and silver in Olbia was 12.2:1, which is somewhat lower, than on Bosporos, but higher, than in Athens for the same time. This hypothetical ratio for Olbia was based on the assumption that it is determining by the real content of these metals in the electrum of the Cyzicenes. But true ratio of gold and silver in Olbia was probably slightly lower. It is possible to determine it, using of one further independent way of calculation for the time of about 325 B.C., when gold and silver staters were issued at the same time. The weight of the gold stater was equal to 8.5 g, the weight of silver one was 12.3 g. Using same method, as for the Bosporan coins, one obtains the figure 8.5xC = 12.3x7.5, and C = 10, which means that the ratio of gold and silver was 10:1, thus similar to the Athenian one. This ratio remained the same later at the transition from the 4th to the 3rd century B.C.
Thus, the exchange rate of the Cyzicenes on Bosporos and in Olbia in the third quarter of the 4th century B.C. was much higher that their value as a metal ingots and to a high degree a conventional one. The official exchange rate of the Cyzicenes was probably the same from the beginning when these coins were first used in the Northern Black Sea littoral as an international currency, when they won undoubted trust among the population. Electrum, which was Cyzicenes struck from, was probably understood as a self-dependent metal, not as an artificial alloy in this area. This was not possible in Attica, where it was a strong tradition of ore treatment and metal cleaning. But in the Northern Black Sea littoral, where there are no deposits of any metal ore and no technological knowledge of its treatment, it is very likely, that electrum was considered as a metal proper, not as an alloy of gold and silver.
Thus, Cyzicenes, perhaps only at the first stage were struck of natural alluvial “white gold”. Then, they were minted of an artificial alloy of gold and silver. This alloy was subjected to changing in its composition: the gold content steadily decreased. The official exchange rate of the Cyzicenes was dropping correspondingly, but only in Athens. In the Northern Black Sea littoral the Cyzicenes were in circulation much longer, and also preserved their initial high rate, which was independent of the gold content in the coins. On Bosporos and in Olbia Cyzicenes had an overvalued exchange rate, on which neither gold concentration in their composition, nor the falling value of gold in the Eastern Mediterranean had any influence.
The silver alloy for the earliest Bosporan coins was of a rather high quality, as the copper content does not exceed 4-5 %. The earliest issues of the first and second groups (middle of the 6th - first quarter of the 5th centuries B.C.) with the lion face on the obverse and squires on the reverse seems to have been struck from an alloy with a lower copper and a higher gold content, than the later ones (see Fig. 2), which could, probably be connected with a change in the sources of silver at the turn from the first to the second quarter of the 5th century B.C.: the Thraco-Macedonian region could be the source for the earlier coins and, perhaps, Laurion the source for the later coins (Kraay and Emeleus, 1962, p.16, 33; Paszthory, 1982).
The next period in the coinage of the Bosporos in the 4th century B.C. is connected with the Bosporan king Leukon I. Under him Bosporos was transformed to a powerful state. After one and a half century of striking only silver, contemporary issues of silver, copper and gold appeared. All the silver coins, which were the basic ones for money circulation, until the 3rd century B.C. demonstrated quite a stable content in their high quality alloy. Gold coins were intended for the foreign market, they were of a very high gold content - no less than 95%. Copper issues of this period were struck of a tin-lead bronze with about the optimal composition for striking coins: several percent of tin and about 5-6 % lead.
In the 3rd century B.C. there was a monetary crisis on the Bosporos. Scholars have suggested the decrease of the wheat grain trade of the Bosporos with Athens, and competition from Egypt, wars with Scythians, and civil wars of the sons of Bosporan king Pairisades as explanations. The issue of silver and gold ceased. The lead content of the alloy of numerous copper coins, issued at the 3rd century B.C. is increasing to 15-20 %, thus perhaps with the aim to make the coinage alloy cheaper, but it led to a deterioration of the alloy instead.
For finding a way out of this crisis the ruler of the Bosporos Leukon II in the end of the 3rd century B.C. issued royal bronze coins of three nominations, all struck of tin-lead bronze of a good quality with a small lead content.
Possibly already in the end of the 3rd or in the beginning of the 2nd century B.C. striking of silver coins was resumed. But for the first time at the history of Bosporos new silver coins were produced from of a bad quality of silver, spoiled by big amount of copper (up to 20-25 %). Possibly at this time the shortage of silver on the Bosporos were observed.
Finally, the end of the monetary crisis was connected with the beginning of the striking of royal gold coins of high quality metal.
In the 2nd century B.C. small silver coins with the head of Apollo and different types on the reverse were struck of a low quality of silver (with copper content up to 40 %) (see Fig. 3). But then the big series of drachms with the head of Apollo - bow case  were issued, and the silver of these coins is rather good. This is not unusual, because many of these coins were overstruck from drachms of Amisos of a high standard of silver.
Copper coins of this period are represented by several issues, and among them coins of the same type as the silver coins Apollo-bow case were struck of bronze with small amount of lead, that is from an alloy which is similar to the metal of Pontic coins. Therefore it is possible to conclude, that the political influence of Pontus started earlier, than the time when Bosporos was included into the reign of Mithridates VI at about 108 B.C.. This influence became apparent in the subject, style, weight parallels of Bosporan and Pontic coins, and also in similar monetary silver and bronze alloys.
When the last Pairisades left the throne to Mithridates VI, the coinage of Bosporos underwent essential changes. The first two Mithridatic periods are from 105-95 and 95-88 B.C. During this period silver and copper issues were struck with signs of undoubtedly Pontic influence in their nominations, topics, style and coins metal.
If the first silver issues of Panticapaion and Gorgippia with the head of Dionysos - skipping deer  were struck of good silver (many of these coins overstroke Amisos drachms), but already the next issues of drachms and didrachms were produced of a very bad quality of silver alloy with more than 50% of copper in the composition. Before 95 B.C. Bosporos probably used the drachms of Amisos for overstriking coins, but after the issue of Amisos drachms has ceased, Bosporan towns had to use their own silver sources for producing this second issue of silver coins. But soon the striking of silver coins ceased on Bosporos in general only to be resumed for short episode in 263-264 A.D.
The copper issues of the first two periods 105-95 and 95-88 B.C. consisted of big nominations: obols and tetrahalkoi, which were struck from "Pontic" bronze with a small amount of lead. Only some Phanagorian coins were struck of a "local" type of bronze, which contained big amount of lead.
It is necessary to link the beginning of the third Mithridatic period in the coinage of Bosporos with the period, when the son of the Pontic king first functioned as a satrap at the height of the First Mithridatic War in 89-88 B.C. (Plut. Sull.11). At that time, or maybe earlier, the issue of the so-called Bosporan anonymous obols with the head of Dionysos/bow in case- Fig. 4, 1 started, which were circulated on Bosporos together with Pontic (mostly Sinopean) tetrachalkoi. The comparison of the monograms on Bosporan anonymous obols with those on Pontic municipal coins allow us to suppose, that Bosporan obols could have be issued from 105-90s until 65 B.C.
One of the main results of the analysis of the coins was that all Bosporan anonymous obols were struck of "pure" copper. 1165 coins of this type or of those, which overstruck them were investigated, and only seven of them were struck of bronze, all the others were struck of "pure" copper. This is absolutely not characteristic of Hellenistic coinage. The only parallels, which we succeeded in finding, were obols of Amisos and Dia in Pontus with the head of Perseus / Pegasus and the so-called Pontic anonymous obols with the head in leather helmet / eight-ray star (Fig. 4), which are accepted to be satrap coins. We could suppose, that Bosporan anonymous obols had some particular status and probably higher value that normal bronze obols, therefore it was necessary to strike them of a rather different alloy when compared with other coins.
It is interesting that the introducing of a new alloy into the coinage dates exactly to the time of Mithridates VI. The composition of metal for the coins of Pontus, Paphlagonia, Bithynia, Phrygia, Mysia, Galatia, Cappadocia in Asia Minor of the time of Mithridates VI were investigated in the British Museum and in the State Hermitage. It turned out that in Amisus, Chabakta and Dia big coins with Perseus / Pegasus (Fig. 4) were struck of "pure" copper, smaller (tertachalkoi?) coins of Amisos and Dia with the Dionysos / cista (Fig. 4), and more rare coins with the head of Amazon (?) wearing a wolf-skin head-dress / figure of Nike (Fig. 4) were struck of brass or aurichalcum. We should notice, that there are two coins with Perseus / Pegasus kept in the State Hermitage collection, issued in Dia, which have unusual reverse type: Pegasus is turned to the right instead to be turned to the left (Fig. 4). Thus, during the period of 90-80s B.C. in several mints of Pontus and Paphlagonia (Amisos, Dia and Chabakta) the simultaneous issue of coins of three different values took place. The coins of each value were struck of different alloy: big coins (obols?) Perseus / Pegasus were struck of "pure" copper, smaller coins Dionysos / cista and Amazone(?) / Nike were struck of brass, and tetrahalcoi Ares / sword and aegis / Nike  were struck of bronze. The coins Dionysos / cista is probably one of the earliest, but not the sole example of using of brass for the first half of the 1st century B.C. As the investigations carried out in the Research Laboratory of the British Museum and our analyses have shown, some towns in Mysia and Phrygia: Pergamum (Fig. 6), Apamea (Fig. 5), Acmoneia (Fig. 5), Dionysopolis (Fig. 5), Eumenia (Fig. 5), and Philomelium (Fig. 5), began to issue coins of peculiar types of brass. It is probably necessary to connect this with the campaign of Mithridates VI in 89 B.C., when the parts of Asia Minor came into the hands of the Pontic king (App. Mithr. 20). This technical innovation in coinage was probably first devised at the court of Mithridates VI, who brought engaged many philosophers, scientists, physicians, craftsmen, and who needed very much additional means for the issue of new and new portions of coins for his huge kingdom. Different alloys, including brass and "pure" copper, enabled a state to make high value nominations without any need for the coin to be unreasonably large, and to make many payments with coins of new alloy, which had previously been made in silver.
Recurring to the coinage of Bosporos, it is necessary to notice, that at the last two years of Mithridates VI’s rule over Bosporos in 64-63 B.C. all anonymous Bosporan obols were overstruck very hastily on the municipal Panticapean obols of the type Apollo / eagle.
After Mithridates VI, the money circulation on the Bosporos consisted only of gold and copper, and this situation continued during the Roman period. The external look of Bosporan staters was formed under Rheskouporis II (68-91 A.D.) and was preserved until the end of Bosporan coinage in the first third of the 4th century A.D. But even cursory acquaintance with this almost uninterrupted sequence of staters lead to the conclusion about the degradation of a style, and also a metal of the alloy, which can be noticed already by the colour and texture of the coins. The last staters had a colour of its metal as simple copper coins, but they preserved the types of golden coins.
The main peculiarities in changing the metal of the staters were investigated by N.A. Frolova, but our work has allowed to establish a more detailed picture, because it was possible to analyse all coins of this kind from the main collection of the State Hermitage (more than 1,500 specimens) (see Fig. 7). These results revealed a stepwise decrease of the gold concentration in the staters. The highest percentage of gold fixed for the Bosporan staters before Asander (in the middle of the 1st century B.C.). Under him the gradual decrease of the gold content started, which continued until the rule of Cotys I (45-62 A.D.). It is possible to explain the stable composition of his staters (about 75 % of gold) as Roman control over the Bosporan coinage. From the time of Rheskouporis II (68-91 A.D.) this control was slackened, which immediately resulted in decrease of the weight and of the gold content of his staters. In the first half of the 2nd century A.D. under Sauromates I (93-123 A.D.), Cotys II (123-132 A.D.) and Rhoemetalces (131-153 A.D.) the percentage of gold in the staters decreased very sharply and reached the level of 45-50 %.
Under Eupator’s reign since Marcus Aurelius came to power in 161 A.D., the issue of staters increased about three times, but the gold content decrease up to 40 %. But the sharpest change in the composition of the staters took place during the money reform of Sauromates II (174 - 210 A.D.) in 186 A.D. That was expressed in extremely abundant issues of staters, which considerably lost their gold content by up to 32%. At the same time copper-based coinage also underwent major changes.
Before him the main coinage alloy for the copper-based issues was bronze with a high lead content. Brass was used from time to time without any special system. All the coins of the first period of the rule of Sauromates II (174-186 A.D.) were struck of bronze.
But after his reform a rich variety of types and subjects of copper-based coins were issued. The system of nominations was also changed: apart from the sestetii, which were considerably decreased in weight, three new nominations arose: drachma = 3 sestertii, denarius = 4 sestertii, double denarius = 8 sestertii. It is very important for us that the weight of the new nominations rose, but not in the proportion of their nominal values. Analyses of coins alloy probably provides the explanation of this.. Double denarii and denarii  turn to be struck of brass, but drachmas were struck of "pure" copper (copper with lead), and sestertii  were struck of bronze (see Fig. 8). Thus, the value of brass coins was about twice as high, or even more, as that of bronze. This is evidently the influence of eastern provincial Roman monetary system, under which many towns issued coins of high nomination from brass, and smaller nomination of bronze.
This separate using of different alloys for striking coins of different nominations did not exist long. At the last period of Sauromates II’s rule, the degradation of the striking of staters is observed as well as the reduction of the weight of copper-based nominations. Some initial types of double denarii were still struck of brass, but soon all coins without any difference were struck of bronze with a high percentage of lead, and this practice continued until the end of copper-based coinage on Bosporos in the end of the 3rd century A.D.
After Sauromates II the process of debasement of the staters was continued at a higher speed. In the 230s A.D. under Cotys III (227-233 A.D.) the final reduction of the gold content in the staters took place. The initial issues of him still have about 20-27 % gold, but after 228 A.D. many staters have only about 15% gold, and some coins contain only a few percent of this metal, and many staters are absolutely without any gold (Fig. 9), which was replaced mostly by silver and copper. The concentration of lead and zinc is on the level of the natural content of these elements.
The final loss of any noble metals in staters took place under Teiranes (275 A.D.). Particularly during his reign the staters of copper-base alloy appeared. The copper-based coinage ceased. This tendency was developed under the next king, Thothorses. Now all staters were struck of bronze with a big amount of lead, that is the alloy, which the copper nominations were struck from under previous kings.
Staters of last two kings (Rhadamsades and Rheskouporis VI) contain fewer additions and their composition is very unstable. It seems that any metal, which could be obtained, was used for coinage. For example, there is a group of staters of Rheskouporis VI of 319 and 320 A.D., which were struck from brass.
It is possible to conclude that the composition of Bosporan staters was controlled by Rome only before Rheskouporis II (before the second half of 1st century A.D.). The phenomenon of a debasement of the metal of the staters and the varying of their amount depended on the inner military and political situation, as also shown by the absence of this control.
Thus, the investigation of the coinage metal could give many additional data about economical and political history of ancient states, about traditions, cultural-technological influences, trade links, crisis in coinage of various centers, and also reflect the changes as a result of monetary reforms.
The investigations of the Olbian coins, the same as the coins of Bosporos and Tyra, were carried out with two independent analytical methods – X-ray fluorescent spectroscopy and measurements of electrical conductivity of the coins. Published data on the composition of coinage alloy of Olbian coins from other collections has been taken into consideration as well.
Olbia was found as a colony of the ancient Greek town of Miletos in the lower Bug region at the transition from the 7th to the 6th century B.C. or in the beginning of the 6th century B.C.
All the cast arrow-coins can be divided into three groups based on the content of silver and antimon in their alloy. The alloy of these coins contains quite considerable amounts of impurities of nickel and cobalt, which is a characteristic feature for the copper ore from the western region. Dolphin-like bars differ chronologically according to the lead content in their alloy. The earliest, anepigraphic “dolphins” contain a small amount of lead (up to 0.7 %). The later ones with the inscription APIXO contain a moderate amount of lead (up to 5%), and “dolphins” with ¤Y - from 10 to 20 % of lead. The earliest round cast asses with the image of a head of Athena with a helmet with the inscription ПАYS were cast of tin-lead bronze (lead content of about 7%). Asses of the second series with a Gorgoneion and the figure of an eagle with a dolphin and with the inscription OLBIO contain very big amounts of lead (more than 25%). And, finally, asses of the fourth group, which are mentioning in the decree of Kanobos, contain lead (about 10%) and quite a large part of zinc (0.6-0.8 %) (Fig. 10).
It is very remarkable, that one third of the investigated coins struck in the first half of the 4th century B.C. (of the type: “head of Demeter in profile / eagle with closely clasped wings, OLBIO”) is produced of a rather unusual alloy, in which there is almost no lead, but zinc is present in some amount (2-2.5 %). It seems that zinc occurred in the metal ore occasionally, and it was not added specially. Many of so-called “Borysthenoi” were overstruck on obols, which are mentioned above. The metal of the “Borysthenoi” contains tin in the amount of about 1-6 %; lead: 1-5 %; and zinc: 1-6% (Fig. 11).
In the middle of the 5th century B.C. silver staters with the inscription EMINAKO were struck of very good silver: the content of silver did not drop lower than to 90% in these coins. But by the end of the 4th century B.C. the deterioration of the alloy of silver coins was fixed. Now they contain only 37-70% silver. This bad quality silver was used until the epoch of Mithridates VI. During the monetary crisis in the 3rd century B.C. “Borysthenoi” very quickly became lighter and more numerous. The content of their alloy also changed – the amount of zinc was decreased (to about 0.5%) and the amount of lead was increased (by 6-8%).
The alloy of coins with images of a head of Demeter in a veil and an ear of corn (with the abbreviations MD and NH) is absolutely different in respect to the alloy of the “Borysthenoi”. This is bronze almost without any addition of lead and without impurities of zinc. The restoration of a mass of full-weight coins in the 230s-220s B.C. of the types “young Heracles / bow in quiver, club” owed to the increasing of the lead content in them (up to 40%). Since that time and by the time of Mithridates VI (and including it) the Olbian coinage bronze contains a very big amount of lead. Only coins, which were, possibly overstruck on the Pontic tetrachalcoi (so-called “pontic bronze”), have 2-5% lead.
There were several issues of coins of Roman time with the head of Zeus and an eagle (rule of the emperor Claudius, 41-54 A.D.). These coins were struck of the low-quality bronze, which contained 20-25% of lead. Several series of copper coins of the time of king Pharzois, who ruled in the middle of the 1st century A.D. and dupondii with schematic images of Apollo/eagle on a dolphin, were struck of the same low quality of bronze. It is necessary to notice, that 3 of 75 coins of this type, which were analyzed, were struck of brass (alloy of copper and zinc).
The Roman provincial typology of Olbian coins was finally established as late as under the Severans. All of the coins of the time of the Severans were struck of tin-lead bronze with a rather moderate content of lead. There are no coins struck of brass at this time at all. The last issues of Olbian coins were under Severus Alexander (222-235 A.D.).
The only Doric settlement at the Northern Pontus littoral was Tauric Chersonesos colonised from Heracleia in 422/421 BC. The silver of the earliest coins is of a rather high quality: about 90% silver and 8% copper. All of the silver coins of the 4th century were struck of good silver, and only in the earliest coin a rather high percentage of gold impurities were found pointing to a possibly Thracian origin of the silver. Bronze coins contain quite a big amount of zinc, as mentioned already, which could also indicate the Northern Thracian copper mines.
But already the next issues of bronze coins from the middle of the 4th century do not contain any zinc. And silver coins with a full-face image of Demeter contain a small amount of gold impurities. Both facts show a change of the metal sources.
In the middle of the 4th century B.C. quite numerous series of small coins with lion head and a star were issued. These coins for the first time contain a lot of lead – sometimes up to 20%.
Later, in the very end of the 4th century or in the beginning of the 3rd century B.C. for the first time in Chersonesean coinage, a series of silver coins with quite a big amount of copper were issued. There were probably difficulties in the supply of silver for striking coins, therefore the silver coins of Chersonesos had not a stable composition of their alloy.
The next period was characterized by the use of quite good copper and silver alloys, but already in the end of 3rd century – beginning of 2nd century coins were again struck of a low quality bronze and silver. The appearance of the Virgin with a tower crown on the coins could tell us about some outer danger, perhaps, the one, which is mentioned in the agreement of 179 B.C. between with the Pontic king Pharnaces I and Chersonesos.
An even worse quality of silver alloy is characteristic for quite numerous coins of the last period of Chersonesos’ autonomy, that is in the end of the 2nd cent. B.C. (two nominations: drachms: head of Virgin with a crown / standing dear and hemidrachms: head of Heracles / club). They contain sometimes more than 50% copper. These coins were issued probably for military payments during the period of Diophantos wars, before Chersonesean dependence on Mithridates VI and Bosporos was established, because on Bosporos and in Pontus quite a good quality of silver was used at that time.
Around 110 B.C. Chersonesos became dependant on the rulers of Bosporos (Strabo, VII, 4, 3), therefore from this time one should consider the coinage of the town within the framework of the coinage of Bosporos. With the help of the composition of the alloy, it is possible more precisely to date the silver drachms “Artemis / Virgin and dear, with the name DHMHTPIOY”. The Russian numismatist Konstantin Golenko date them quite late because of the similarity of the images of the head of Artemis on the Bosporan drachmes “Dionysos / tyrsos” and tetrachakes “Dionysos / tripod, tyrsos”, which, according to our classification could be dated by 96/95-89/88. But, as we know, silver of the Bosporan coins was of very bad quality, while the alloy of Chersonesos coins of magistrates DHMHTPIOY is of a quite high percentage of silver, which is characteristic rather to the Bosporan drachms of the earlier period, 102/101 – 96/95 B.C. of the type “Dionysos / running deer, tyrsos”. This fact, together with the obvious similarity of the images of the heads of Artemis and Dionysos could indicate an earlier date of the Chersonesean drachms of the magistrate DHMHTPIOY.
When anonymous obols were struck on Bosporos, in Chersonesos and Olbia also coins without name of the towns have been struck. After 89/88 B.C. a big anonymous coin with the head of (Mithridates ?)/Virgin in her full size was struck in Chersonesos of an alloy containing several percent zinc. These coins probably served instead of silver coins, which were absent in Chersonesos. Smaller nominations are represented by tetrachalcoi with images and composition of bronze, typical for Pontos.
After the death of Mithridates VI, all the states on the Northern shores of the Black Sea became influenced by the Romans. The obols or dupondii with the inscription CERSONhSOU ELEUqeras belong to the time of the Chersonesean autonomy in 45-44 B.C., but these coins were struck of bronze of a very different composition than the previous issues: they contain up to 20% or more of lead. This composition is characteristic to all coins until the middle of the 2nd century A.D. The same feature has been noted also for Bosporus.
In 144 A.D. the Bithynian town of Heraclea sent an embassy to Rome to the emperor Antoninus Pius (138-161 A.D.) (IOSPE, I², 362, 363) and as a result, Chersonesos obtained the status of a “free city”. This is the so-called period of the second eleutheria. The coinage changed very much. Now coins of four denominations are struck, and each of them has it’s own type. Then, the character of the alloy changed for all the coins of this period until 222 A.D. Big nominations are struck of a multi-components alloy with a small amount of lead, which is similar to the alloy of Roman asses, small nominations are struck of bronze with a big amount of lead. The coinage of Chersonesos of this period is similar to the Olbian one, but later in time, from the period of Septimius Severus.
The next issues of Chersonesian coins are different than the issues of the “second eleutheria” coins. Now only coins with types of tetrassaries are issued, but they stick to a bronze with a high content of lead and the quality of images became lower. All this show that there were some serious changes in the organization of the coinage in Chersonesos. On Bosporos we fixed a very sharp change in 228-230 in the composition of the alloy of the staters, when gold disappeared from them. We connected these changes with barbarian invasion, so-called “Scythian” or “Gothic” wars. Rome did not help Bosporus any longer, and we could suppose, that the Romans did not supply Chersonesos with the coinage metal either. Therefore we could date this change in the coinage of Chersonesos to a date close to 228-230 A.D.
The last issue of Chersonesos was during the time of Gallienus (253-268 A.D.), as many other Greek towns, which were dependant on Rome.
We have investigated coins of the 4th century of two types “Sitting Scythian / horse” and “head of the Goddes / dear”. They were struck of approximately the same kind of bronze with a small amount of lead. An interesting thing was that in two specimens we found about 1 % of zinc. The same phenomenon was seen among the coins of Olbia and Chersonesos, which could result from using the same source of metal.
The town of Tyras was situated on the right bank of the Dniester liman. It was founded probably in the 5th century B.C. and it existed continuously until the end of the 4th century A.D.
The first coins of Tyras were struck around a middle of the 4th century B.C. Before this time foreign coins of Cyzicos, Histria and other towns circulated in Tyras. The first drachms of Tyras were struck of a high quality alloy, in which the silver content was from 80 to 90%, that is the same silver content, as in the alloy of the contemporary coins of Panticapaion, Chersonesos and Olbia.
The earliest copper coins of Tyras were struck in the second half of the 4th century B.C. These are the coins with images of the river god Tyras and a head of a horse. They were contemporaneous to the silver drachms mentioned above. Later, in the 3rd century B.C. the smaller coins bearing the same types were struck. Probably at the same time or a little later the coins with a head of Tyras/bull and a head of Athena with a helmet/bull were produced. The alloy of all these coins is tin bronze with a very small amount of lead. The same phenomenon could be observed concerning the copper coins of Bosporos, Chersonesos and Olbia for the period of the 4th century B.C.
In the second half of the 3rd century B.C., for the first time in the history of Tyrean coinage lead in rather big amount (5-13%) appeared in bronze coins of Tyras of the type: head of Demeter (full face) / cista. Since this period and during the 2nd century B.C. the lead-tin bronze was used in Tyras for striking coins.
During the first half of the 1st century B.C. Tyras was involved in the sphere of interest of the Pontic king Mithridates VI. The coinage of Tyras of this time was autonomous by appearance, but with a strong Pontic influence, which was reflected in typology, weight norms, technical and stylistic peculiarities of the coins, and also in the coinage alloy. Now it is tin-lead bronze with a very small amount of lead (no more than 1%). The bronze of this type was used for striking coins in Pontus, let us therefore consider, that during Mithridates’ reign Tyras was supplied with coinage metal from the Pontic kingdom.
Around the middle of the 1st century B.C. Burebistan tribes destroyed Tyra, together with the other Western Pontic towns. The production of coins ceased and it was restored again only by the middle of the 1st century A.D. But by then, Tyras did not strike her own coins, but Roman sestertii and dupondii of the emperor Claudius with stamps “TYP” circulated in the town. As it is known, in the 1st century A.D. Roman sestertii were struck of brass with a zinc content of up to 26%, whereas asses were struck of “pure” copper. Naturally, the same composition can be found in the Tyrean coins as mentioned above.
Tyras recommenced striking coins under the emperor Vespasian (69-79 A.D.). Under Domitian (81-96 A.D.), Hadrian (117-138 A.D.) and Antoninus Pius (138-161 A.D.) coins of several values were struck, and coins of each value had it’s own type on the reverse. But there was no difference in the use of coinage alloy: all the coins were struck of tin-lead bronze with a small amount of lead (several percent).
The use of letters to designate Tyrean coins of different values, like in the Western Pontic cities, was obligatory from the time of the emperor Commodus (180-192 A.D.). But the difference is that in Tyras the weight of the coins was lower, and only one kind of alloy was used: tin-lead bronze. (In the Western Pontic cities the use of brass is fixed for striking coins of higher values, and bronze for coins of the smallest value).
Since the time of Septimius Severus (193-211 A.D.) a considerable increase of the volume of coins production in Tyras is observed. P.O. Karyshkovsky thought, that it was to be seen in connection with the general politics of Septimius Severus to oblige provincial towns to pay the Roman army quite a big part of their salary, which was increased sharply in the first half of the 3rd century. The coins of Tyras of this time can be divided into several series. The first two series are dated to 193-197 and 198-201 A.D. They are characterized by issuing coins of big values, thoroughness in die engraving, and accurate and legible performance of portraits and inscriptions. It is very interesting and important, that during this period for the first time in the history of Tyrean coinage, the coins of all values were struck of a new alloy in Tyras, namely of brass. All the following issues were struck again of bronze. How one can explain this phenomenon?
The results of our analyses of coins from the Western Pontic cities show, that the Roman provincial towns used brass for striking coins of big values. But this rule was spread to Tyras only once, under the first part of emperor Septimius Severus’s rule. It is necessary to notice, that brass was not used at all in Olbia for striking coins. The Tyrean coins of the time of Septimius Severus, Caracalla and Severus Alexander were much more diverse by the types and number of series, they are characterized by thoroughness in die engraving, more than the contemporary coins of Olbia. That was determined by the special attention and support paid by the Roman authorities to Tyra situated nearer, than to rather remote Olbia, which was surrounded by barbarian tribes, and which the Romans did not hope to hold in their hands.
The last emissions of Tyras and Olbia show the difference between the coinage of
these two towns in the very last period of their history. In Olbia the finds of
foreign and Olbian coins ceased by the time of Severus Alexander (222-235 A.D.),
which shows that the existence of the town as a trade center stopped under the
emperor Maximinus (235-238 A.D.). Although the coinage of the town itself ceased
in Tyras after Severus Alexander too, for at least the next two decades coins of
the last issues, which were struck with additional stamps, circulated. They were
circulating in Tyras together with coins of the neighboring towns and with Roman
coins. The same situation was observed in the towns of Moesia, which kept their
importance in trade until the time of Gallienus (260-268 A.D.).
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 The investigations were carried out with help of portative analyzer for X-ray fluorescent spectroscopy “Spectroscan” of Saint Petersburg plant Spectron, which allowed to obtain a full X-ray spectrum of the elements and to estimate their percentage content in a specimen from Ca to U.
 Plinius, (XXXIII, 80): omni auro inest argentum vario pondere aliubi decuma parte, aliubi octava; ubucumque quinta portio est, electrum vocatur; Isidorus, Origines XVI, 24.
 Diod., 3,4 following Agatharcides.
 Strabo, III, 2,8.
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 Condamin J. and Picon M., Notes on diffusion in ancient aloys. Archaeometry, v. 8, 1965, p.110-114
 Head B.V. A Catalogue ... London, 1892, p. XXVII, XXVIII.
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 Regling K. Der griechische Goldschatz von Prinkipo. Zeitschrift für Numismatik, XLI, 1931, p.1-46
1931; A. Brett, op.cit.
 Meyers P., op.cit.
Bulatovich S.A., op.cit.
Bogaert R. Le cource du statėre de Cyzique à Athėnes aux Vet IVsiecles avant J.-C. Ėtat de la question. RBN, vol. 123, 1977, publ. 1978, p.17-39.
 Bodenstedt F. Phokäisches Elektron-Geld von 600-326 v. Chr., Mainz, 1976, р.61-64.
 Thompson W.E. The value of Kyzikene stater. Numismatic Chronicle. 1963, v. III, p. 1-4
 Demosth., XXXIV
 Bogaert R. Le course du statère de Cyzique aux Vet IVsiècles avant J.-C., L’Antiquite classique. XXXIV, 1963, p.85-119, p.97; B.V. Head, Historia Nummorum, 2nd ed., Oxford, 1911; Gardiner P. A History of Ancient Coinage. Oxford. 1918; Franke P.R., Hirmer M., Die griechische Munze. Munich, 1964. P.144; Guepin J.P. Le course du cyzicene. L’Antiquite classique. XXXIV, 1965. S.199-203; Eddy S., The value of the Cyzicene stater at Athens in the fifth century. The American Numismatic Society Museum Notes, N 16, 1970, p.13-22, p.14; Vinogradov Ju.G., Karyshkovsky P.O., art. cit., p. 29
Thompson W. E., Gold and silver rations at Athens during the fifth century. Numismatic Chronicle. 1964. Vol. IV. P. 103-123, р. 103
 Thompson W. E. , op.cit, р. 113
 Lewis D. M. New evidence for the gold-silver ratio.Essays in Greek Coinage presented to Stanely Robinson, Oxford, 1968, p.105-110.
 Bodestedt F., op.cit., p.72
 Delphian inscription of 336/5 B.C., SIG, 1 , 351, H, II, 9-11
 Melville-Jones J.R., The value of gold at Athens in 329/8 BC. American Journal of Ancient History, v. 3, N 2, 1978, p.184-186, p.185.
 Guepin J.P., Greek coinage and persian bimetallism. Jaarboek voor munt – en penningkunde, N 48, Amsterdam, 1961, p.1-19 ,p.1-2
 16.02 g after von Fritze H., op.cit., p.31-34
 Head B.V., Historia nummorum, p. 370; Gardiner P. A., A History of Ancient Coinage, p. 224
 see map on the p.36 of Laloux M., op.cit.
 Shelov D.B., op.cit., p.95
 Shelov D.B., op.cit., p.97; see map on the p.48 of M. Laloux, op.cit.
 Shelov D.B., op.cit., p.96-97
 P.O. Karyshkovsky, Ob obraschenii kizikinov i Olvii (About a circulation of Cyzicenes in Olbia). Numismatika i Epigrafika (Numismatics and Epigraphics). II. 1960. p. 3-13, p. 12-13
 Latyshev B. Inscriptiones antiquae orae septentrionalis Ponti Euxini Graecae et Latinae. Tyrae, Olbiae, Chersonesi Tauricae. Petropoli, 1916., I , 24; Vinogradov Ju.G., Karyshkovsky P.O., op.cit., p. 28
 Demosth., XXXIV
 Marchetti P., op.cit.; Anochin V.A. Otnisitelnaja stoimost’ zolotai serebra v Olvii i na Bospore v kontse V – IV v. do n.e.(Relative value of gold and silver in Olbia and on Bosporos at the end of 5th – 4th centurie B.C. ), Numizmatika i Sfragistika (Numismatics and Sphragistics), v. IV, 1971, p. 3-14, p.6.
 Zograf A.N., op.cit., p. 175
 Djukov Ju.L., Smekalova T.N. Rezultaty issledovanija sostava bosporskich monet VI-II vekov do n.e. iz sobranija Gosudarstvennogo Ermitazha (The results of investigation of the composition of Bosporan coins of 6th – 2nd centuries B.C. from the collection of the State Hermitage), Drevnosti Bospora (Atniquities of Bosporos), v. 1, Moscow, 1998, p. 226-236, p. 230.
 Vinogradov Ju.G., Karyshkovsky P.O., op.cit., p. 37
 Vinogradov Ju.G., Karyshkovsky P.O., op.cit., p. 32-33
 Latyshev B., op.cit., 24
 Vinogradov Ju.G., Karyshkovsky P.O., op.cit., p. 28
 Vinogradov Ju.G., Karyshkovsky P.O., op.cit., p. 32
 Frolova N.A. Monetnoe delo Bospora serediny 6th – 5th v. do n.e. (Coinage of Bosporos of the middle of 6th – 5th centuries B.C.)/Rossijskaja arheologia (Russian archaeology) 1996. № 2. С. 34-69. p. 51, 54, 55
 Shelov D.B., op.cit., tabl. III, 35-37, tabl.IV, 40-42, 44, 45, tabl.V, 58, 59
 Ibid, tabl. III, 29-33
 Ibid, tabl.III, 38, 39, tabl. IV, 51, tabl. V, 60, 61
 Ibid, p. 149, 150; Anochin V.A., op.cit. 1986, p.55)
 Shelov D.B., op.cit., tabl. V, 63, 64, tabl. VI, 65
 Ibid, tabl. VII, 76-78
 Ibid, tabl. VII, 80, 82
 Ibid, p.183-190, tabl.IX, 104-108
 Ibid, tabl.VIII, 90-93
 Ibid, tabl. VII, 86-88
 Golenko K.V. Neskolko serebrjanyh monet Pantikapeja II veka do n.e. s sledami perechekanki (Some silver coins of Panticapaion of the 2nd century B.C. with traces of overstiking). Numismatika i Epigrafika (Numismatics and Epigraphics). v. VII. 1968. P. 37-42. P. 39
 Shelov D.B., op.cit., tabl.VIII, 94
 Ibid, 1956, c.203
 Anochin V.A., 1986, op.cit., tabl. 7, 196-197
 Ibid, tabl.7, 198, 199, 205, 206
 Frolova N.A. The coinage of the kingdom of Bosporus A.D. 242–341/342 // British archaeological reports. Intern. Ser. 1983. № 166. P. 10-11, Pl. XIII, 13-15, XV, 3
 Anochin V.A., 1986, op.cit., tabl.7, 191, 201, 207, tabl. 8, 210
 Ibid, tabl. 7, 192, 202, 208, tabl. 8, 211
 Ibid, tabl.7, 194
 Ibid, tabl. 8, 212
 Frolova N.A., 1996, op.cit., p. 168
 Waddington W., Babelon E., Reinach Th. Recuel general des monnais grecques d'Asie Mineure. – Paris: Ernest Leroux, 1925. 211 p. Tabl. VII, 25-26, XI, 21
 Golenko K.V. Pontijskaja anonimnaja med’ (Pontic anonymous copper coins) // Vestnik drevnej istorii (Ancient history harald), 1969. P. 41, 44; Zograf A.N., op.cit., 1951. P. 186
 Burnett A.M., Craddock P.T., Preston K. New light on the origins of orichalcum // Proc. 9. Intern. Congress of Numismatics, Berne, September 1979. – Berne, 1980. P. 263-268. Craddok P.T., Burnett A.M., Preston K. Hellenistic Copper-base coinage and the origin of brass // Sci. Studies in Numismatics / Ed. W.A. Oddy (British Museum Occasional Paper No.18). – London, 1980. P. 53-64. Cowell M.R., Craddock P.T., Pike A.W.G., Burnett A.M. An analytical survey of Roman provincial copper-alloy coins, and the continuity of brass manufacture in Asia Minor // XII. Intern. Numismatic Congress. Berlin, 8-12 September, 1997. Proceedings. – Berlin, 2000. P. 670-677.
 Waddington W., Babelon E., Reinach Th. op. cit., tabl. VII, 25, 26, XI, 21, VII, 25, 26
 Ibid, tabl. VII, 30
 Ibid, tabl. VII, 23
 Ibid, tabl. VIII, 1-4
 see reference number 79
 Wroth W. A catalogue of Greek Coins in the British Museum: Pontus, Paphlagonia, Bithynia, and the Kingdom of Bosporus. London, 1889. 252 p. N 129-134, 144-149, 195-204, 187-188
 Head B.V. A catalogue of Greek Coins in the British Museum: Phrygia. – London, 1906. 489 p., 53 pl. P. 74, 75, N 2-5
 Ibid, p. 4, 5, N 6-9
 Ibid, p. 182, N 3-5
 Ibid, p. 211, N 3-6
 Ibid, p. 353, N 3-6
 Burnett A.M., Craddock P.T., Preston K. op.cit., p. 268
 Anochin V.A., 1986, op.cit., tabl. 9, 214
 Frolova N.A. The Coinage of the kingdom of Bosporus A.D. 69–238 // British archaeological reports. Intern. Ser. 1979. № 56. 249 p., 63 pl. Frolova N.A., 1983, op.cit.
 Frolova N.A. O prichinah reformy denezhnogo obraschenija na Bospore v pravlenie Savromata II (On the reasons of the money reform under Sauromates II) // Numizmaticheskij sbornik GIM (Numismatic book of GIM). 1977. Part 5, vyp. 1. P. 150-232. P. 156
 Burachkov P.O. Obschij katalog monet, prinadlezhaschih ellinskim kolonijam, suschestvovavshim v drevnosti na severnom beregu Chernogo morja (General catalog of coins, belonged to the Hellenic colonies, which were existed at the ancient times on the shores of Black Sea), Odessa, 1884, part 1. Tabl. XXX 225, 228, 239
 Ibid, tabl. XXX, 246
 Ibid, tabl.XXX, 222
 Olgovsy S.Ja. Metall lityh monet Nizhnego Pobuzh’ja (Metall of the cast coins of Lower Bug) //Olvia i ee okruga (Olbia and it’s chora). Kiev, 1986. P. 89-105
 Vinogradov Ju. G. Politicheskaja istorija Olvijskogo polisa (Political history of Olbian Polis). Moscow, 1989.284 p. P. 36
 Bartseva T.B. Tsvetnaja metalloobrabotka Skifskogo vremeni. (Colour metal treatment of Scythian Times) – Moscow, 1981. 125 p. P.22
 Latyshev B., op.cit., 24
 Anochin V.A. Monety antichnyh gorodov severo-zapadnogo Prichernomor’ja (Coins of the Ancient Greek cities of the Northern Black Sea coastal line). Kiev, 1989. 126 p. Tabl. IV, 29-52
 Karyshkovsky P.O. Monety Olvii (Coins of Olbia). Kiev. 1988. 167 p. P. 68, fig. 7, 2.
 Karyshkovsky P.O. Olvijskie monety: proizvodstvo i metrologija (Olbian coins: production and metrology) // Stratum. Saint-Petersburg, Kishinev, Odessa. 1999. P. 20-77. Tabl. 1.
 Karyshkovsky P.O., 1988, op.cit., p. 68, fig. 7, 8
 Anochin V.A. 1989, op. cit., tabl. XVII, 259-261
 Ibid, tabl. XXI, 340, 343
 Ibid, tabl. XXI, 353, 354
 Ibid, tabl. XXI, 359, tabl. XXII, 362, 364, 366
 Anochin V.A. Monetnoe delo Chersonesa (Cinage of Chersonesos), Kiev: Naukova Dumka, 1977. p.20; table I, 2-7
 Kraay C.M., Emeleus V.M., 1962, op. cit., p.16, 33
 Anochin V.A., 1977, op. cit., tabl. II, 27-32
 Anochin V.A., 1977, op. cit., tabl. V, 82-86, 88-90
 Anochin V.A., 1977, op. cit., tabl. IX, 133-142, 150-152, 156-157; X, 158
 Anochin V.A., 1977, op. cit., tabl. XII, 179-183
 Anochin V.A., 1977, op. cit., tabl. XII, 191
 Golenko K.V., Chersonessian drahes with the name of magnestrates Demetrius. Correspondense of
the Pushkin Museum of Fine Art. Moscow-Leningrad, 1964, pp. 45-50
 Anochin V.A., 1977, op. cit., tabl. XIII, 199
 Anochin V.A., 1977, op. cit., tabl. XVII, 250-261, XX, 273-283, 286-288, 290-295
 Anochin V.A., 1977, op. cit., tabl. XIII, 200
 Anochin V.A., 1977, op. cit., tabl. XXI, 296-303
 Zograf A.N., 1951, op. cit. табл. XXXVIII, 17, 18, 20.
 Karyshkovsky P.O., Kleiman I.B. Drevnij gorod Tira (Ancient town of Tyra). Kiev, 1985. 160 p. P. 58-
59, tabl. 21, 1-3
 Ibid, tabl. 21, 8
 Ibid, tabl. 21, 7,9
 Ibid, tabl. 21, 4, 5
 Anochin V.A. 1989, op. cit., tabl. XXVII, 474
 Zograf A.N. 1951, op. cit., tabl. XXVII, 9
 Zograf A.N. 1951, op. cit., p. 117