gondonneau, guerra (2002) circulation precious metals arab empire.pdf

8/16/2019 GONDONNEAU, GUERRA (2002) Circulation Precious Metals Arab Empire.pdf

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The circulation of precious metals in the Arab Empire 573 Archaeometry 44, 4 (2002) 573–599. Printed in Great Britain

* Received 19 July 2001; accepted 10 May 2002.© University of Oxford, 2002

THE CIRCULATION OF PRECIOUS METALS IN THE ARAB

EMPIRE: THE CASE OF THE NEAR AND THE MIDDLE EAST*

A. GONDONNEAU and M. F. GUERRA

Centre de Recherche et de Restauration des Musées de France, UMR 171 CNRS,

Palais du Louvre—6, rue des Pyramides, 75041 Paris Cedex 01, France

The analysis by nuclear activation techniques and by inductively coupled plasma mass

spectrometry combined with an UV laser of a large number of gold coins issued in the Arab

Empire from the seventh to the 12th century AD showed that several different supplying

sources were used, according to the region and to the period.

The aim of this paper is to point out the circulation of gold in the Near and Middle

Eastern mints of the Arab Empire and to make a parallel with the mints’ policies running inthe other regions of the Empire, such as North Africa, the Iberian Peninsula and the Sicily.

The identification of different gold ores by means of characteristic trace elements indic-

ated recycling of the ancient coinage and, after AD 750, the minting in the entire Arab

Empire of different new gold ores: Egyptian type, North Eastern type and West African type.

The analysis of a small number of silver coins from the same periods and regions also showed

a change in the ore supply after AD 750.

KEYWORDS: GOLD, SILVER, ACTIVATION ANALYSIS, ICP-MS, MUSLIM, COINS

INTRODUCTION

To study the circulation of gold in the past, we must characterize this metal. In general, thecharacterization of a metal can be done by two sorts of techniques: the determination of thelead isotope ratios or the determination of a combination of characteristic trace elements enter-ing in the metal’s composition.

However, the identification of the sources of gold is not an easy task. Nowadays, many of theancient sources are completely exhausted, few documents make reference to the situation of the mines and so no geochemical information is available. This means that the search for thecirculation routes of gold is mostly based on the objects themselves.

This particular study on the circulation of gold in the Near and Middle Eastern regions of theArab Empire is based on the analysis of coins. As in our case the documents give informationon the sources of gold and on the routes of the caravans, we can assume that the coins struck inthe mints close to the gold mines or close to the main routes of the gold caravans are made withlocal gold (Gondonneau and Guerra 2000). So, if the composition of these coins matches withthe composition of other coins we can assume that they were produced with the same gold.

The size and the rarity of the coins compel the use of non-destructive analysis. Also, the largenumber of analyses required to obtain the statistical composition of the assumed local goldinhibits sampling. This means that isotopic measurements are hard to perform, especially if weconsider the fact that native gold shows very low lead contents (Antweiler and Sutton 1970).


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574 A. Gondonneau and M. F. Guerra

We must also be aware of the recycling of coins, as the main information on the character-

istic elements might be lost. However, the advantage of our coins is that the date and mint of

issue are indicated in the coins’ legends, and the high level of production of gold makesrecycling of the specimens unnecessary.

If many techniques can determine the major, minor and sometimes a few trace elements, thecharacterization of gold might require the measurement of several elements for which classical

techniques present too low detection limits (Gondonneau et al. 1996). In fact, the high temper-

atures to which the ores and metals are submitted during separation and purification lead to theloss of a large number of elements by oxidation and evaporation. Mostly elements following

gold — such as the platinum group elements (PGE), as well as a few other elements such astin, antimony, tellurium and zinc — give, in general, information on the ore type and on theprovenance of the metal, but those elements are not easy to measure when present in ppm

concentrations. If we need to be aware of the PGE inclusions (Meeks and Tite 1980), we could

observe by filtered PIXE mapping on samples with Pt contents between 3000 and 100 ppm

(Guerra and Calligaro 2002) that below about 500 ppm the distribution of that element is quitehomogeneous.

In order to obtain as much information as possible on the gold ores, we used 12 MeV proton

activation analysis (Barrandon et al. 1976) and, for some specimens, LA-ICP-MS analysis,

which provides quantitative determinations of the major, minor and trace elements in gold

(Guerra et al. 1999).

Using those analytical techniques, and being aware of all the dif ficulties, we have focusedour work on the provenance of the gold ores used in the Orient but also in the Occident by the

Arabs to issue their gold coin. That gold coin, the dinar, remained the monetary dominant

specie of the Mediterranean world and the Near East until the 12th century ad.

THE MUSLIM EMPIRE

Islam was undoubtedly the most profound social and religious revolution to take place in the

history of the Arabs, if not in the entire Near East (Frye 1993).

From the sixth century to the beginning of the seventh century, the conflicts with theByzantines, who dominated the Mediterranean Near East, and with the Sassanians, who dominated

Mesopotamia and Iran, contributed to the loss of their territories, which were conquered by the

Arabs. The expansion of Islam started after the death of the Prophet in ad 632 and finished inad 732 with the defeat imposed by the Franks in the battle of Poitiers (France), which stopped the

advance of the Arabs to the north-west. After the fall of Jerusalem in ad 638, in about 30 yearsthe Arab armies reached northern India and controlled Syria and Persia. Then Alexandria was

conquered in ad 711, and after the occupation of Egypt the Arab armies reached the North of

Africa through Libya and then defeated the Visigoth kings in Spain. Although in ad 717 the

Arabs were defeated in Constantinople, they were still able to conquer Sicily and Crete.

However, those victories were obtained by different dynasties (see Table 1). The internal

struggles for power of the different clans gave rise to a first period (ad 661 – 750) of a central-ized Ummayad government that ruled from its capital, Damascus. The Persian Abbasids, who

replaced the Ummayad dynasty, ruled until 1258 from a new capital, Baghdad. The decentral-

ization of the Arab Empire began with the Abbasids and several states were created, each one

having a ruler.It was by the end of the eighth century ad that the vast Arab Empire extended from the Indus

to the Aegean Sea, from the Oxus to the Arabian Peninsula, from Egypt to the Maghrib, and


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The circulation of precious metals in the Arab Empire 575

included the Iberian Peninsula (see Fig. 1). With one language and one religion, it became an

enormous economic system that controlled all of the trade in the Mediterranean world.

The dinar, the Arab gold coin, became the medium of exchange for commercial transactions

in the Mediterranean world and also in Europe. Cipolla (1956) considers the dinar as one of the

‘dollars’ of the Middle Ages.The first gold coin, with Arabic writing and no figures, appeared under the Ummayads after

the reform of ‘Abd al-Malik in ad 695, while the Islamic silver coin called the dirham was firstissued in ad 698. During the first period, gold was struck in the Islamic empire in at least four areas: Egypt (Mis’r), Syria (Damascus), North Africa (Ifriqhiya) and Spain (al-Andalus). If theUmmayad centralized the fabrication of the gold issues, this central government monopoly was

abandoned by the Abbasids. In fact, while only three mints (Baghdad, Egypt and Ifriqhiya)

issued dinars under Harun al Raschid (ad 786 – 809), in ad 889 about 20 mints were producingdinars at the same time as the governors of Egypt, North Africa and Spain. The standard purity

of the of ficial coinage was arbitrarily fixed by the rulers. This gave rise in the Abbasid East tothe circulation of several different dinar issues (Ehrenkreutz 1959).

Several documents refer to the re-exploitation of, for example, the Nubian, Red Sea, Ethiopian

and Arabian (Yemen) gold mines in the Orient by the first caliphs of the Islamic expansion.However, the most important event of the economic situation in the Arab Empire was certainly

the exploitation of a new gold ore from the Occidental regions: the new sources of ancient Sudan

(Ghana, Mali and Mauritania). We know that all the commercial exchanges were done in dinars,

which at that time reached distant regions such as the Indian Ocean, Ceylon and Malabar. But

did the exploitation of that new Occidental gold give rise to the issue of such quantities of dinars?

Did that gold reach Egypt and the Middle East? Was it used to fabricate the Oriental dinar?

In the 10th century ad the Islamic world started to break up, with the establishment of the

Fatimids first in North Africa and then in Egypt, and with the important role of the Ummayads inSpain. We can observe in the 11th century the decline of the Islamic world with the establish-

ment of the Turks in the Near East, the Berbers in North Africa and Spain and the Christians in

Sicily and Syria. The Fatimids in Egypt remained the last bastion of the Arab world.

ANALYTICAL TECHNIQUES

Two techniques were used to perform the analysis on the gold and silver coins: 12 MeV proton

activation analysis and LA-ICP-MS. The first method uses the CERI — CNRS cyclotron facilities

Table 1 Muslim dynasties and periods of reign

Dynasty Dates ( AD) Main regions controlled

Ummayad 661 – 750 Near East, North AfricaAbbassid 750 – 1258 Near East, EgyptMidrarid 771 – 976 North AfricaAghlabid 800 – 909 North Africa, (Sicily)Tulunid 868 – 905 Egypt (Near East)Ikhshidid 934 – 968 EgyptFatimid 909 – 1171 North Africa, Egypt (Sicily, Near East)Zirid 972 – 1167 North AfricaAlmoravid 1061 – 1147 North Africa, al-AndalusAlmohad 1147 – 1269 North Africa, al-Andalus


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and the second one the IRAMAT — CNRS Fison PlasmaQuad PQXS, combined with a 2 mJpulsed VG Nd : YAG laser. The laser, with a maximum shot frequency of 10 Hz, has its

wavelength frequency quadrupled to work at the UV wavelength of 266 nm.

The analysis of gold coins by proton activation analysis was first developed by Meyers in the1960s (see Meyers 1969, 1972). In our configuration the first experiments were done byBarrandon and Debrun in the 1970s, but readers can refer to Poirier (1983). The analysis uses

a 12 MeV proton beam extracted through a Ti target that reaches the sample with an energy of

11.36 MeV. At this energy we observe almost only (p,n) nuclear reactions, which reduce the

interference and improve the detection limits. Gold produces two isomers of mercury-197 by a

(p,n) reaction, both of which emit gamma rays of an energy lower than 300 keV. The inter-

position of a lead sheet between the sample and the detector strongly absorbs low-energy gamma

rays and so gamma-ray spectrometry can be performed on the gold object immediately after

irradiation. Quantitative calculations were made by using a basic equation containing the proton

range in the sample, solved using the Ricci and Hann (1965, 1967) mean σ method; concentra-

tions are normalized to 100 wt%. With this technique we can measure the major elements of gold alloys (gold, silver and copper) as well as about 12 minor and trace elements with detec-

tion limits that may reach 1 ppm. Those trace elements are characteristic of some monetary

debasement techniques and sometimes discriminate the gold ores.

The first gold fingerprinting by means of LA-ICP-MS was done by Watling et al. (1994) ongeological samples, but qualitatively. In the same year, Kogan et al. (1994) published their

technique for measuring in a quantitative way trace elements in high-purity gold and silver

industrial samples. Based on ‘home-made’ nuclear activation certified gold samples of differentcompositions, we were able to develop, in 1998, a semi-quantitative technique with our LA-

ICP-MS configuration, details of which were published in Gondonneau and Guerra (1999). The

main parameters are described in Table 2; for those UV laser parameters the depth of the crater was estimated (by piling 20 µm thick certified 80Au/20Cu foils) to about 130 µm. Quantitative

Table 2 The main operating conditions and data collection parameters for the LA-ICP-MS con figuration

Instrument Fison Elemental PlasmaQuad PQXS

Plasma Argon

Forward/reflected radio frequency power 1.350 kW/


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calculations were made by using the internal standard technique, which in the case of the gold

samples was the argon species AuAr + generated in the plasma (gold is a mono-isotopic element

that is present in too high levels to be measured in pulse counting mode; that is, at the same

time as trace elements).

The detection limits were evaluated by considering first a concentration equivalent to threetimes the standard deviation of 10 replicate blank analyses, and then a concentration equival-

ent to three times the standard deviation of three replicate analyses (the normal analytical

procedural conditions for objects) of the high-purity gold standard NBS SRM685. The latter

corresponds to the normal ‘gold’ plasma conditions observed during the analysis of gold objects.

Figure 2 shows that the plasma-only and gold background measurements give detection limitsthat differ by a factor of 10. In the same figure we can observe a factor of 10 – 100 between theLA-ICP-MS and the proton activation analysis (PAA) detection limits.

THE GOLD COINAGE

For this study we analysed 234 dinars issued by the Arab dynasties in different Near and

Middle Eastern, North African and Sicilian mints. The comparison with the situation in the

other regions of the Arab Empire was made by adding to our results the composition of a few

coins issued in North Africa and Spain, already published by Roux and Guerra (1998, 2000).

In Table 3 we can observe that most of the dinars present a gold concentration higher than95%, the others having a reduced purity that may fall as low as 75%. This debasement is

observed for 30% of the Abbasid dinars, or 39% if we exclude Egypt. Those debased dinars

were struck in the Middle Eastern mints. The Abbasids controlled this region above all, but the

decrease in the gold concentration with a corresponding increase in silver (copper is, in general,

present in very low concentrations, lower than 1%) could be explained by the non-purificationof the native gold ores. In fact, we know that on the one hand the refining techniques areexpensive and that, on the other hand, gold ores have a concentration of silver that may reach

more than 40%, with a copper content lower than 1% (Raub 1995). We must note that only

native gold from Borneo and the Urals shows 5% or more copper, as observed by Palache et al.

(1944, cited by Ogden 1993).However, it is hard to check for the use of non-purified gold (Oddy 1980; and see the

appendix). If we consider that coins were instead debased by the addition of silver and that

Figure 2 LA-ICP-MS detection limits measured using either repeated blanks or gold standard NBS SRM685 and

compared with PAA detection limits.


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most of the silver ores exploited in ancient times were lead ores, we expect to find in Table 1(results obtained by PAA; see the appendix) a correlation between silver and lead (Antweiler

and Sutton 1970; Hartmann and Nau 1976; Healy 1978). During refining, lead is not completelyeliminated from silver, so the quantity of lead measured in a debased gold object can be

supposed to depend only on the quantity of silver. This correlation is not observed. However,we cannot state that silver from another type of ore was not added to the alloy (even if there is

no correlation between silver and any other measured trace element).

No link was found between the purity and the date of issue or the mint situation, but the

politics of the Oriental caliphs itself explains that debasement. Under the Abbasids the disorder

caused by the emergence, mainly after ad 861, of large social revolts and separatist movements

in such a huge territory resulted in the Baghdad authorities losing political and administrat-

ive control over the monetary mints. The geographical fragmentation of the Empire led the

governors of the various states to establish the dinar ’s purity as a function of their own needsand ideas (Ehrenkreutz 1963). This is the reason why several different dinars were in circulation

at the same time in the Orient.Considering that, in general, the dinars seem to have been made with native gold, which was

either purified or not, we can assume that their trace elements are characteristic of the employedgold ore. A specific gold ore corresponds to each chemical group, and coins matching with onechemical group are assumed to be made from the same gold ore. The aim of this work is to

determine, by means of the characteristic trace elements measured in a group of dinars, the origin

of the gold ores used in the Near and Middle Eastern mints and to understand the circulation of

gold in that region of the Arab Empire.

GOLD AND SILVER AT THE BEGINNING OF THE CONQUEST

When the Arabs reached the various regions that they conquered, they replaced the existing

coins with their dinars and dirhams (gold and silver coins, respectively). Did they recycle the

previous coins or did they use new ore supplies to strike their coinage? In order to answer this

question, we analysed a group of coins struck before and immediately after the conquest.

Orient and North Africa

Before the Arab conquest, the Oriental and North African regions were under the control of

the Sassanians and the Byzantines. The Byzantine coinage was mostly made of gold, but the

Sassanian coinage was mostly fabricated with silver.In order to check whether or not this coinage was recycled, the composition of some of the

last Sassanian and Byzantine coins was compared with the composition of the first Muslim ones.

Gold In Figures 3 (a) and (b), we can observe a correlation between the Pt and the Pd con-

tents for the dinars issued in North Africa and in the Orient. The Ummayad dinars show higher

contents than those issued by the Abbasids in the Middle East and the Aghlabids in Ifriqhiya. If

we include in Figure 3 (b) the Byzantine coins struck in Carthage before the conquest and the

Arab – Latin coins struck in that mint immediately after the conquest (the Arabic legends onlyappear after the reforms of ‘Abd al-Malik in ad 695), we can see that they are also characterized

by high Pt and Pd contents.We can suggest that the Ummayads recycled the Byzantine gold from Carthage. In Table 4

we compare the Pt/Au ratio obtained for the Ummayad and Byzantine Carthage coins with a


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(a)

group of Byzantine coins struck in Constantinople and analysed by Morrisson et al. (1985)

using the same technique (unfortunately, those authors did not measure the Pd contents). Wecan see that the Pt/Au ratio ranges between 2 and 8 for all the Byzantine coins struck in

Constantinople and, if we exclude one coin, between 2 and 6 for all the Ummayad dinars.

(b)

Figure 3 Platinum and palladium contents normalized to gold concentration for (a) the Near and Middle Eastern

Ummayad and Abbasid dinars and (b) the coins issued in North Africa by the different Arab dynasties and by the Byzantines.

Table 4 The Pt/Au ratio for the Byzantine coins struck in Carthage and Constantinople, and for the Eastern and

Western Ummayad, Aghlabid and Abbasid dinars

Pt/Au

Dynasty Area


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We can say that those results go together with the hypotheses of Bates (1992, 1995) about

the preservation of the same mint personnel after the conquest. In fact, if the Arabs’ conquestwas prompt, the ‘arabization’ of the administration was rather slow. The use of Latin legends towrite on the first coins the sayings of the Prophet, and the similar concentrations of Pt and Pdfound in the Byzantine and the Ummayad coins, lead us to suggest that the gold ore used to

issue the first Muslim dinars either in the Orient (Damascus was under Byzantine domination

before the conquest) or in Ifriqhiya is the same. We can see in the same Table 4 that the Pt/Auratio changes under the Abbasids and the Aghlabids, which certainly corresponds to a change in

the ore type around ad 750.

Silver As little or no gold was struck in Persia by the Sassanians before the arrival of the Arabs,

we analysed a few dirhams issued by the Ummayads and the Abbasids in the Oriental mints,

and compared the results with those obtained for a small group of Sassanian and Arab – Sassaniancoins.

In Figure 4 (a) we show the Au/Ag ratio as a function of the date of issue of the Muslim and

the Sassanian coins: to obtain approximate ad dates, we have added 622 to ah (anno Hegirae)

dates. We observe that the ratio changes from an average of 0.006 for the Sassanian, Arab – Sassanian and Ummayad coins to an average of 0.002 for the Abbasid ones. This change has

already been referred to by Gordus (1972) and Meyers (2002); in fact, we can see in the same

(a)

(b)

Figure 4 The Au/Ag ratio as a function of the date of issue of (a) the Eastern Ummayad and Sassanian silver coins

and (b) the North African Ummayad and Abbasid dirhams.


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figure that our results and those of Gordus fit together. We can assume a change in the silver ore supplies by the end of the Ummayad reign and the beginning of the Abbasid dynasty in the

Middle East.

However, if we cite Meyers (1998) it is assumed that silver metallurgy started with the

exploitation of lead – silver ores: cerussite (PbCO3) and galena (PbS). The Au/Ag ratios meas-ured by several authors, as cited by Meyers (1998), in lead ores as well as in slags and litharge

show that silver produced from galena contains less than 0.1% of Au, while silver from

cerussite has an Au content higher than 0.25%. This means that cerrusite was exploited before

galena to produce silver objects.The sudden change of the Au/Ag ratio around ad 750 may indicate a change in the type of

lead ore exploited and thus in the production technique. The problem of the scarcity of silver

faced by the Arabs (shown by the production, in the seventh – ninth centuries, of high-tin bronzepatinated vessels that look like silver; Meyers 1998) could have been solved by the fact that

they had the technology needed to exploit deeper mines.

If we consider in Figure 4 (b) the results obtained for the dirhams of the North African mints

published by Roux and Guerra (1998), we can observe the same phenomenon for Ifriqhiya: a

decrease in the Au/Ag ratio between the Ummayad and the Abbasid dynasties in the middle of

the eighth century (around ah 140/ ad 757).

Spain

When the Arabs reached the Iberian Peninsula in ad 711, they found a very debased coin, the

Visigoth tremisse. The analyses published by Guerra (2000a,b) of some tremisses from several

different regions — Lusitania, Galecia, Betica and Carthaginense — can be compared with ana-lyses of a small set of Arabian coins struck under the Damascus- dependent Ummayad Emirate,

immediately after the conquest, and of a small group of dinars struck by the Spanish Ummayad

(Guerra and Roux 2002). The Pt, Pd, Sn, Zn and Sb contents show a change in the gold

supplies. This change can be described completely by the evolution of the Sn and Pt contents in

Figure 5: the tremisses struck in the south of the Iberian Peninsula are similar to the first dinars,which seems to show that the gold could have been recycled. We also notice that the gold struck

in the north by the Visigoths came from a different source, certainly from the northeastern

Figure 5 The concentration of platinum and tin for the northern and southern Visigothic tremisses and for the first

Arab coins struck in the Iberian Peninsula by the Ummayad Emirate.


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mines of the Iberian Peninsula. According to D. M. Metcalf (personal communication with

M. F. Guerra) the northeastern mines only produced about 10% of the gold needed to make

the northeastern tremisses (see Guerra 2000a), the rest coming from the southern mines. On the

other hand, under the Ummayads a new gold supply is observed that certainly corresponds to

West African gold (see Guerra 2000a,b; Guerra and Roux 2002).We can conclude that the first gold and silver Arab coins, struck immediately after the

conquest, were made in all the regions of the Empire by recycling the previous coins (or, less

probably, by the use of the same ores). Also, a change in the metal supplies appears for gold

and for silver by the middle of the eighth century ad, which means between the end of the

Ummayad dynasty and the beginning of the Abbasid dynasty in North Africa and Spain, as well

as in the Middle East.

GOLD IN THE MIDDLE EAST FROM THE ABBASIDS TO THE FATIMIDS

Our results show that a new gold supply arrived under the Abbasids in the Oriental Muslimmints, and the aim of this section is to try to identify the sources of this gold.

Due to the scarcity of Oriental coins in the French collections, the results are treated by geo-

graphical region (see Fig. 1). We applied a correspondence analysis statistical treatment called

‘Anaconda’ (version 1.0 for the Mac system by J.-J. Girardot, Laboratoire de Mathématique,Informatique et Statistique, Université de France-Comté, Besançon, France) to all the elementsin Table 2, normalized to the gold contents, except for lead. In fact, we observed that this

element is present at high concentrations in some coins with more than 98% Au; for example,

coin L895 with 10 500 ppm and coin L966 with 12 900 ppm. An analysis of about 25 gold

nuggets from Ghana, the Ivory Coast and Mali (see Guerra 2002) by PAA and ICP-MS in

liquid mode shows that the Pb concentration is always lower than 76 ppm, except for onesample. This one nugget showed a Pb content of 2200 ppm (the major composition being:

94.2% Au, 5.8% Ag and 0.003% Cu). No explanation has yet been found for this phenomenon,

but in Ogden (1993) we read that ‘0.2% lead was reported in a sample of native electrum fromWest Africa’.

Several authors, amongst whom is Ehrenkreutz (1959), suggest that the dinars struck imme-

diately after the conquest without the mint mark were issued in the Empire’s capitals: firstDamascus (in Syria) under the Ummayads and afterwards Baghdad and Samara (in Iraq) under

the Abbasids. In ah 146/ ad 763, the opening of the Baghdad mint under the Abbasids and the

caption with the name of the issuing mint on the coins clarify their provenance.

Figure 6 shows the results of the statistical treatment on the first dinars issued by theUmmayads and the Abbasids in Damascus (Syria?), before the opening of the Baghdad mint;

the coins struck by the Abbasids in Baghdad, but without a mint mark (Iraq?); and the dinars

struck by the Abbasids in all the other mints of the Eastern Empire, with a mint mark. The

Ummayad dinars have higher Pt and Pd contents than the majority of the Abbasid dinars.

However, the latter present higher Ga and Sn contents. We can suggest that the gold ore of

Byzantine type struck immediately after the conquest by recycling of the previous coins was

gradually replaced by another gold ore with higher Ga and Sb contents and a lower Pt content.

The first Abbasid dinars from Syria without a mint mark are in group 1, but those with a mintmark are present in groups 1 and 2, as are those from Iraq without a mint mark.

All the dinars struck in Egypt, Yemen and Khuzistan fit together in group 2 and those fromJibal, Azerbaijan, Al Jezirah and Cilicia are chemically close to that group. Most of the dinars

struck in Al Shash (Transoxiana) and some coins from the northern mints of the Empire,


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Figure 7 The results of the statistical analysis on the dinars issued in Egypt by the different dynasties.

with those from Baghdad and Al Basra. Figure 8 shows that the Sn/Au ratio of the Fatimid

coins struck in Egypt increases with the date of issue. We do not know where this gold comesfrom, but we could imagine the arrival of a gold supply from the Western Empire.

GOLD IN THE WESTERN EMPIRE

It is hard to determine which of the sources of gold, Nubia or Ghana, was the most important

one at every stage of the Fatimid period (Messier 1973). While the Fatimids arrived in Egypt

in ad 969, this dynasty had reigned over Ifriqhiya since ad 909 and, following Ehrenkreutz, it

is clear that their domination all over the North African coast gave them the benefit of theimported gold ores from western and eastern Africa. Also, after their establishment in Egypt,

the Fatimids concluded an alliance with the Zirids, the governors of Ifriqhiya, that lasted until1041. From the cessation of this relationship emerged the Hilalian invasion in 1051 – 2 and theFatimids’ loss of the West African routes from ancient Sudan.

Figure 8 The Sn/Au ratio as a function of the date of issue for the Egyptian Fatimid dinars.


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Figure 9 The results of the statistical analysis on the dinars issued by the Fatimids in Sicily, Egypt (Mis ’r and

Alexandria) and North Africa (Ifriqhiya). (?) corresponds to coins without a mint mark.

We have plotted in Figure 9 the results of the statistical analysis on the Fatimid coins struck

in Egypt, North Africa and Sicily, as well as those struck by the other dynasties that controlled

North Africa. The dinars from Mis’r form a group characterized by higher Pt and Pd contents,

while some Aghlabid dinars (the dynasty that accepted the caliphate of Baghdad authority andruled over Ifriqhiya from ad 800 to ad 909) form a second group, characterized by a higher Ga

content. The other Aghlabid coins fit into the Egyptian group. The Aghlabids seem to have useddifferent gold ores for the fabrication of their coins: first, a (certainly) local gold with a high Gacontent, followed by an Egyptian-type gold and a mixture of both gold ores (or recycling of the

previous coins). The Fatimids seem to have followed the same procedure in North Africa.

However, a few Fatimid and Zirid dinars, as well as the Midrarid ones, fit together with thegroup formed by the Almoravid coins. These dynasties had access to West African gold. The

Almoravid gold is characterized by a lower Ga content and the absence of PGE, but is still

chemically different from the coins struck in Alexandria. The Sicilian coins have tin contents

that increase with the date of issue, so we can suggest the use of the same gold ores as used bythe Aghlabids and the Fatimids, and the slow arrival of a new ore coming from West Africa.

If we consider Messier ’s suggestions, the Almoravids gained a certain prestige from their monetary gold, which had a very good reputation among medieval authors, and certainly

among merchants, who invariably referred to the Sudanese gold as a very pure gold of the best

quality. We must note that the analysis of a group of modern gold nuggets from Ghana, the

Ivory Coast and Mali showed a very pure gold with a purity that may reach more than 98% and

very low quantities of PGE and Sb (Guerra 2002). The Almoravid gold struck in the African

mints on the West African gold caravan routes, such as Sijilmasa, is certainly the famous

Sudanese gold. This gold arrived in Spain (Roux and Guerra 2000) and in Sicily. If Messier

supposes that the local supply in Fatimid Egypt might not have been suf ficient to cover thegovernment needs, which means that the Fatimids could have continued to import West African

gold, the analysis does not show the use of that gold in the eastern Empire mints.


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CONCLUSIONS

We have been able to identify several gold ores supplies employed by the Arabs to strike their

coinage from the beginning of the conquest to the 12th century, particularly those used in the

eastern part of the Empire.

The comparison of the characteristic trace elements concentrations present in the silver and

gold coinage issued before and immediately after the conquest in the different regions of the

Empire showed that until about ad 750 all of the Islamic world recycled the previous coins:

Byzantine and Sassanian coins in the Orient, Byzantine coins in North Africa and Visigoth

coins in Spain. During the transition period between the end of the Ummayad dynasty and the

arrival of the Abbasids (around ad 750), we have observed a change in the silver and gold

supplies all over the Arab Empire. This phenomenon certainly corresponds to the exploitation

of deeper silver veins and of new sources of gold such as the West African one.

We could show that in the Near and Middle Eastern mints under the Abbasids an Egyptian-

type gold — certainly from Nubia, the Red Sea or Arabia — was used, while another gold orewas used in the northeastern Empire. But in Egypt under the Fatimids we observed the

recycling of the Abbasid dinars, corresponding to the reforms of ad 969, as well as the use,

in Alexandria, of another gold ore with high Sn and Sb contents.

In the western Empire we have observed that under the Aghlabids a short-lived gold is used,

certainly an Ifriqhiyan one, while in the mints located on the gold caravan routes a West African

gold was struck. This gold reached Spain and Sicily. But while there are no signs of its arrival in

the eastern Empire, under the Fatimids the eastern gold seems to have reached the western mints.

ACKNOWLEDGEMENTS

The authors are grateful to Michel Amandry and François Thierry, respectively Director andChief Curator of the Cabinet des Médailles, Bibliothèque nationale de France, for all their helpwith the coin collections; to Michael Bates, Curator of Islamic Coins in the American Numis-

matic Society Museum; to Luke Treadwell, Keeper in Islamic Numismatics at the Heberden

Coin Room of the Ashmolean Museum of Oxford; to Pieter Meyers, Head of Conservation at

the Los Angeles County Museum; and to Michael Cowell, Research Scientist at the Department

of Scientific Research of the British Museum, for all their suggestions and information; and tothe IRAMAT laboratory and the CERI-CNRS cyclotron laboratory for the running time.

APPENDIX

In Gondonneau et al. (2001) we showed the difference between the concentration of some

elements obtained by LA-ICP-MS and by PAA. This difference is due to the non-linearity of

the laser ablation. In order to have an homogeneous set of results we give in Tables 5 and 6 the

compositions obtained by PAA. The composition of the coins already published in Gondonneau

and Guerra (1999) may therefore sometimes be different.

We need to be aware of the quantities of lead in gold. As Grimwald (2000) says: ‘Workabilitywill be deleteriously affected if the alloy contains embrittling impurities or hard spots. One

well-known example is that the presence of small amounts (


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Table 5 The composition of the analysed gold coinage. The coins belong to the Bibliothèque nationale de France collecti

catalogue of Lavoix (1891)

%

Dynasty Region Reference Date ( AH ) Mints Au Ag Cu As Ga Pb

Byzantine North Africa 1968.798 38/40 Carthage? 98.3 1.4 0.3 3 2 4

Sch2831 47/53 Carthage? 95.5 3.7 0.8 5 3

Af725 54/58 Carthage? 96.7 2.6 0.7 3 1 9

Arab-Latin North Africa L109 85/87 Carthage? 88.6 10.4 3.0 1 2 12

L110 87/88 Carthage? 90.5 7.6 1.8 2 1 12

L111bis 90/91 Carthage? 84.9 12.0 3.2 3 2 8

L114 98 Carthage? 60.6 37.4 2.0 7 8 1

Ummayad North Africa 1978.51 101 ? 98.8 1.0 0.04 1 1

L408bis 101 ? 98.7 1.1 0.1 1 2 1

1966.341 102 ? 98.8 1.1 0.04 1 0.4

L425 103 ? 99.6 0.4 0.01 1 0.5

1978.52 104 ? 99.0 0.8 0.2 1 1 1

L464 114 ? 98.8 1.0 0.1 13 3 1

L465 117 ? 98.4 1.2 0.2


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Table 5 (continued)

%


Aghlabid North Africa L823 191 Ifriqhiya? 93.8 5.7 0.4 6 16 3

L830 199 Ifriqhiya? 98.2 1.6 0.0 1 15 37

1972.1319 200 Ifriqhiya? 97.7 2.1 0.1 4 6 23

L202bis 202 Ifriqhiya? 96.2 3.2 0.5 1 11 3

L836 213 Ifriqhiya? 97.2 2.5 0.2 1 23 6

1974.31 218 Ifriqhiya? 97.9 1.8 0.2 2 24 5

1974.32 222 Ifriqhiya? 97.4 1.8 0.2 1 18 63

L845 230 Ifriqhiya? 99.1 0.8 0.1 1 7 13

1972.1321 236 Ifriqhiya? 98.2 1.3 0.3 2 9 1

L846 240 Ifriqhiya? 98.4 1.3 0.3 1 19 1

1978.53 242 Ifriqhiya? 98.2 1.2 0.5 2 26 3

1974.35 249 Ifriqhiya? 99.1 0.6 0.2 1 15 11974.36 250 Ifriqhiya? 98.7 0.8 0.3 2 20

1970.269.2 253 Ifriqhiya? 97.9 1.5 0.5 0.5 15 75

L857 261 Ifriqhiya? 98.5 0.7 0.7 1 10

1967.210 269 Ifriqhiya? 98.6 0.8 0.5 2 47 1

L865 271 Ifriqhiya? 98.5 0.7 0.6 1 9

L867 276 Ifriqhiya? 98.4 1.0 0.3 1 81 1

1972.1326 280 Ifriqhiya? 98.4 1.3 0.3 1 8 4

1976.189 282 Ifriqhiya? 98.4 1.4 0.1 6 6 1

L873 284 Ifriqhiya? 97.1 1.4 1.4 2 59 1

1972.1328 288 Ifriqhiya? 97.3 2.2 0.4 1 13 9

L883 290 Ifriqhiya? 98.4 1.2 0.3 2 2 12

1967.570 293 Ifriqhiya? 97.1 2.3 0.6 6 21 9L887 296 Ifriqhiya? 97.5 2.0 0.5 2 7 6

Abbasid Egypt L885 199 Mis’r 95.8 2.3 0.02 21 2 16 64

L890 203 Mis’r 96.8 2.9 0.1 8 21 39

L895 215 Mis’r 98.1 0.7 0.04 17 10 10 48

L949 235 Mis’r 99.1 0.9 0.04 3 6 3

L954 245 Mis’r 99.7 0.2 0.004 3 7 7

L982 252 Mis’r 99.9 0.0 0.002 10 8


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Azerbaijan L995 272 Azerbaijan 93.9 5.0 0.9 7 3 30

L1115 311 Ardabil 90.0 8.0 2.0 22


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Table 5 (continued)

%


Iraq L944 240 Surra min raa 98.9 0.6 0.1 11 5 2 02

L966 248 Surra min raa 98.2 0.3 0.02 9 5 12 88

L978 252 Surra min raa 81.1 17.8 0.9 8 6 22

L1000 265 Surra min raa 96.0 3.6 0.3 7 4 25

L1023 258 Wasit 96.2 3.2 0.4 4 4 51

Khorazan L946 238 Merv 98.0 1.9 0.1 3 2 14

L947 243 Merv 99.9 0.1 0.01 1


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L971 251 Samarkand 98.6 1.3 0.002 3 6 14

L979 253 Samarkand 97.1 2.6 0.1 8 2 1 81

L1001 271 Samarkand 98.0 1.8 0.1 4 4 6

L1002 273 Samarkand 98.8 1.1 0.1 3 5 3

L1003 276 Samarkand 99.1 0.7 0.1 4 2 11

Yemen L926 221 San’a 97.8 2.0 0.1 2 15 4

L927 223 San’a 89.7 9.2 1.0 13 27 21Vogüe1920 224 San’a 87.6 11.6 0.2 12 35 2 90

L973 249 San’a 98.7 1.2 0.04 3 17 <

L1004 273 San’a 98.8 0.8 0.1 7 16 13

L1005 275 San’a 99.0 0.9 0.0 4 7 2

L1121 314 San’a 87.3 9.9 2.6 34 34 11

Tulunid Egypt L4 260 Mis’r 99.9 0.0 0.003 0.3 4 <

L5 266 Mis’r 99.7 0.2 0.003 5 10 2

L25 272 Mis’r 98.1 1.6 0.1 2 9 2

L30 278 Mis’r 96.3 3.3 0.2 1 4 9

L33 281 Mis’r 99.4 0.5 0.02 1 10 1

L46 290 Mis’r 94.9 4.7 0.3 7 5 4

L47 291 Mis’r 93.5 6.0 0.3 4 9 3

Ikhshidid Egypt 1974.1036.6 344 Mis’r 99.5 0.3 0.03


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23/27

L150 386 Mis’r 98.2 1.5 0.2 4 1

L174 387 Mis’r 98.1 1.7 0.2 1 2 1

L179 393 Mis’r 97.1 2.3 0.4 1 5 9

L182 396 Mis’r 98.2 1.5 0.2 0.5 3 2

L184 401 Mis’r 97.9 1.6 0.2 1 4 1

L187 405 Mis’r 98.4 1.3 0.1 1 2

L188 411 Mis’r 97.9 1.7 0.2 1 20 5

L242 415 Mis’r 98.1 1.4 0.2 1 3 2

L244 416 Mis’r 97.8 1.8 0.2 1 3 4

L245 420 Mis’r 74.9 20.0 5.1 2 2 13

L351 428 Mis’r 98.2 1.6 0.1 1 5 2

L355 436 Mis’r 98.2 1.5 0.2 1 6 4

L358 438 Mis’r 98.6 1.2 0.05 5 6 2

L360 440 Mis’r 96.9 2.6 0.2 2 11 7

L361 440 Mis’r 98.8 1.0 0.1 1 1 57

L362 442 Mis’r 98.7 1.0 0.1 2 10 4

L366 447 Mis’r 98.2 1.3 0.2 9 3 1 74

L370 452 Mis’r 98.7 1.0 0.1 5 3 1

L373 456 Mis’r 86.2 11.8 1.5 36 8 1 84

L375 462 Mis’r 97.7 2.1 0.1 0.4 4 3

L376 475 Mis’r 98.6 1.1 0.1 4 1 2

L377 481 Mis’r 96.9 2.7 0.3 4 2 4

L378 481 Mis’r 97.5 2.1 0.3 8 3 6

L380 484 Mis’r 97.1 2.5 0.3 7 6 4

L418 495 Mis’r 99.7 0.2 0.02 2 0.1

L425 510 Mis’r 78.7 19.9 1.3 14 1 15

L429 515 Mis’r 85.7 12.5 1.2 7 2 8

L255 469 Al Iskandariyah 99.3 0.5 0.02 3 2 5

L256 469 Al Iskandariyah 99.1 0.7 0.05 0.3 3








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Table 5 (continued)

%


Sicily L95 343 Sicily 98.1 1.4 0.3 10 37 11

L134 367 Sicily 97.5 1.9 0.5 19 22 18

L135 380 Sicily 96.5 2.7 0.5 15 38 25

L217 420 Sicily 90.1 7.9 1.7 20 23 25

L293 446 Sicily 91.3 7.4 0.7 19 8 8

Palestine L349 462 Acre 95.8 3.5 0.5 8 5 3

L350 487 Acre 96.7 3.0 0.2 5 1 24

Midrarid North Africa L929 336 Sijilmasa 94.9 4.5 0.4 6 26 3

L930 340 Sijilmasa 96.4 3.1 0.4 5 4 1

1982.1578 343 ? 97.6 1.8 0.3 5 23 1

Zirid North Africa 1966.352 439 Sabra 98.9 1.0 0.03 7 2 1966.58 441 ? 98.3 1.4 0.2 0.2 1

1978.54 442 ? 98.2 1.3 0.1 8 52 2

1985.545 444 ? 94.2 4.9 0.6 6 30 7

1972.1338 370 ? 97.7 1.8 0.3 4 19 3

L151 375 ? 97.8 1.9 0.2 3 41 3

Almoravid North Africa L508 456 Sijilmasa 97.4 2.4 0.1 9 4 2

L509 462 Sijilmasa 94.6 4.9 0.5 5 2 4

L510 468 Sijilmasa 95.8 3.8 0.2 8 1 6

L511ter 473 Sijilmasa 94.8 4.8 0.3 13 2 1

L512 476 Sijilmasa 95.2 4.4 0.2 4 1 8

SL1926.1338 476 Sijilmasa 96.2 3.5 0.2 2 1

L530 495 Sijilmasa 84.9 12.9 2.1


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