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[Supplementary material]

The long-distance exchange of amazonite and increasing social complexity in the Sudanese

Neolithic

Andrea Zerboni1,*, Sandro Salvatori2, Pietro Vignola3, Abdelrahman Ali Mohammed4 & Donatella

Usai2,5

1 Dipartimento di Scienze della Terra ‘A. Desio’, Università degli Studi di Milano, Via L.

Mangiagalli 34, I-20133 Milano, Italy

2 Centro Studi Sudanesi e Sub-Sahariani, Treviso, Via Canizzano, 128/D, 31100 Treviso, Italy

3 C.N.R.-Istituto per la Dinamica dei Processi Ambientali, Via S. Botticelli 23, I-20133 Milano,

Italy

4 National Corporation for Antiquities and Museums, Khartoum, Sudan

5 Dipartimento di Scienze dell’Antichità, Sapienza Università di Roma, Via dei Volsci 122, I-00185

Roma, Italy

* Author for correspondence (Email: andrea.zerboni@unimi.it)

1. Analysed materials

Chemical analysis on a selected set of amazonite beads (9 samples) from R12 were carried out to

test the hypothesis advanced by Arkell (1953, 1964) that amazonite as a raw material originated

from the Tibesti massif. The study sample set includes: two beads from Grave 83 (Middle Neolithic

A: Period 1-B2; beads R12a and R12b), one from Grave 116 (Middle Neolithic A: Period 1-B2;

bead R12c); a fourth bead was collected on the site surface before the excavation started (bead

R12d). A further 5 beads (R12e–i) come from an eroded grave that can be dated, according to the

associated pottery materials, to the Middle Neolithic B (Period 2: Multaga Phase) of the R12

cemetery. These archaeological amazonite samples were compared to a number of samples from the

amazonite-bearing pegmatites that outcrop in many places across northern and eastern Africa (see

for a geological discussion on their distribution: Zerboni et al. 2017), obtained from museums and

private collections. Pegmatite samples here discussed are from the Tibesti massif (Eghei Zuma

area) in southern Libya; Talat Umm Jaraf, Jebel Hafafit, and Jebel Migif in southeastern Egypt;

Konso and Kenticha in Ethiopia and a region between Jordan and Saudi Arabia, not far from Wadi

Tabuik. These amazonite outcrops are already known and in some cases (Eghei Zuma and the

Egyptian sites) they display evidence for archaeological or modern quarrying. A single outcrop of

pegmatite with amazonite known in Sudan is located in the Jebel Nuhud and a specimen from this

locality was also analysed. Other comparison samples correspond to beads and pendants traded

2

today across North Africa and belong to ethnographic private collections. These include a modern

Tebu bead used as a pendant, nowadays traded in the old market of Omdurman, in Sudan, an

ancient bead from Mauritania, and 5 beads part of a traditional necklace from Mali.

2. Description of the analytical method

According to the protocol described in Zerboni and Vignola (2013) and Zerboni et al. (2017),

chemical analyses on micro-samples of 50-100µm in diameter, sampled from the inner part of each

bead and from the hand specimens from natural outcrops, were performed. Amazonite micro-flakes

were enclosed in epoxy, polished, and carbon coated. Quantitative electron microprobe chemical

analyses in wavelength dispersive mode (EMPA-WDS) were performed using a JEOL JXA-8200

electron microprobe on at least four points for each sample. The typical perthitic texture of

amazonite (i.e., alternating lenses of microcline and albite; Figure S1) is fine, and for that reason we

adopted the microprobe thanks to the possibility to identify with high precision on the back-

scattered electron (BSE) images the position of each point analysed. This procedure assured to

collect information only on the blue microcline fraction (Zerboni et al. 2017). For these samples,

due to the micro-perthitic texture of the amazonite, it is of great importance to locate the electron

beam with micrometric precision, in order to avoid the micrometric-thick albite strips, which may

contaminate the result of each analysis (Zerboni et al. 2017).

Figure S1. Back-scattered electron (BSE) image showing the perthitic texture of one of the

amazonite sample from R12. Note the occurrence of a mixture of dark and light gray areas,

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corresponding to albite and microcline respectively; the very light gray lamella is muscovite. The

beam diameter of c. 1 µm of the microprobe permits analysis of microcline and avoids

contaminations from albite crystals (within rock matrix).

The system was operated with an accelerating voltage of 15keV, a beam current of 5nA, a beam

diameter of 1µm, a counting time of 30sec on the peaks and 15sec on the backgrounds for the

principal elements (Si, Ti, Al, Fe, Mn, Mg, Ca, Na, and K), and 30sec on the peaks and 30sec on the

backgrounds for the minor elements (Pb, Sr, Cs, Ba, P, Rb and Cl). The natural minerals grossular

for Si (Kα1, TAP), Al (Kα1, TAP) and Ca (Kα1, PET), K-feldspar for K (Kα1, PETH), forsterite

for Mg (Kα1, TAP), omphacite for Na (Kα1, TAP), ilmenite for Ti (Kα1, PET), fayalite for Fe

(Kα1, LIFH), rhodonite for Mn (Kα1, LIFH), cancrinite for Cl (Kα1, PET), pollucite for Cs (Lα1,

PET), celestine for Sr (Lα1, PET), baryte for Ba (Lα1, PET), galena for Pb (Mα1, PET), “apatite”

for P (Kα1, PET), and synthetic compound Rb2MnF6 for Rb (Lα1, PET) were used as standards.

The elements Ti, Cl, and P were below detection limits in all analyzed points. The raw data were

corrected for matrix effects using the ΦρZ method as implemented in the JEOL suite of programs;

mean values between analysed points were calculated (for all analyses the 3σ value was below 1)

and summarized into Table 1 of supplementary material.

The chemical composition of all the samples analysed (raw materials and ornaments) in terms of

orthoclase, albite, anorthite percentage (Or, An, Ab) of blue-green areas samples plot in the area

belonging to perthitic orthoclase-microcline in the ternary plot diagram used for the nomenclature

of ordered ternary feldspars (Deer et al. 1992). The absence of Ca (anorthite) in the composition of

the amazonite samples indicates a temperature of crystallization below 750°C at 1 kbar in the field

of crystallization for the shallow level NYF pegmatites at each site and their attribution to

amazonite (Fuhrman and Lindsley 1988; Wise 1999; Simmons et al. 2003; Černy and Ercit 2005).

The geochemical trace elements signature of single minerals (in this case, potassic microcline) from

a pegmatitic dike closely reflects the composition of the granitic source (Martin et al. 2008). For

this reason, each chemical composition obtained is completely representative of the mean

geochemical character of the magmatic rocks in its source area.

3. Petrogenetic development of amazonite

Amazonite is a semi-precious green to blue-green variety of microcline with white veins, and is

commonly found as a rock-forming mineral in the niobium-yttrium-fluorine or NYF geochemical

type of granitic pegmatites (Černy and Ercit 2005), or in pegmatites that reacted with deposits of

massive sulphides containing Pb (Wise 1999; Martin et al. 2008). Pb also determines the typical

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colour of amazonite thanks to its incorporation into the structure of microcline at the expense of K.

The replacement of K by Pb induces a structural vacancy that is filled by H2O, which turns the

whitish colour of microcline into the greenish-blue colour of amazonite (Hofmeister and Rossman

1985).

Figure S2. Ternary plot of the composition of K-feldspars in terms of Or-Ab-An (modified from

Deer et al. 1992); Or is orthoclase, Ab is albite, An is Anorthite. Dots corresponds to the

composition of analysed samples; the whole set of samples falls in the area of microperthite or

pertithic microcline.

NYF-type granitic pegmatites are generated by magmatic differentiation of calcalkaline to

peralkaline granitic masses related to anorogenic or late-orogenic tectonic environments (Martin

and De Vito 2005). The magmatic differentiation of these granitic masses generates swarms of

pegmatitic dikes, which present a homogeneous geochemical fingerprint matching the parent

granite and are highly enriched in fluorine, yttrium, and niobium. The dikes are zoned, and low-

temperature green feldspar forms big masses or single crystals in the intermediate zone (Simmons

et al. 2003).

On the basis of analytical data (Table 1 of the main text), the chemical composition of all the

amazonite samples analysed matches that of a perthitic orthoclase-microcline in the ternary plot of

Fig. SM2, used for the nomenclature of ordered ternary feldspars (Deer et al. 1992; Wise 1999;

Simmons et al. 2003; Černy and Ercit 2005). The absence of Ca confirms the attribution of the raw

material to amazonite (Fuhrman and Lindsley, 1988). At the microscale of analysis, raw material

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outcrops belonging to our dataset presents large crystals of amazonitic microcline embedded in the

pegmatitic matrix and displaying the typical perthitic pattern (Figure S3).

Figure S3. Photomicrograph of amazonitic microcline from selected outcrops in thin section (under

cross polarized light) displaying the typical perthitic pattern (note also the tartar twin pattern of A).

Sample provenance: A, Eghei Zuma; B, Jebel Hafafit; C, Jebel Migif; D, Konso.

4. Possible sources of amazonite raw material in northeastern Africa and adjoining regions

In Africa, amazonite-bearing pegmatites relate to a series of late- to post-orogenic calc-alkaline to

peralkaline intrusive magmatic plutons that formed during the late stages of the Pan-African

Neoproterozoic orogenic event c. 550mya (Zerboni and Vignola 2013). NYF granitic pegmatites

originated after magmatic differentiation of these calc-alkaline intrusive rocks and intruded into the

meta-sedimentary or volcanic sequences up to continental-scale mobile belts, joining the Archean

cratons. Calcalkaline granitic plutons form a series of outcrops that are roughly aligned in a NE–

SW direction, and stretch from the Sinai Peninsula to Nigeria. It is within these late orogenic

plutons that the NYF pegmatite swarms originated, and raw material sources of amazonite can be

found (Zerboni et al. 2017).

Amazonite-bearing pegmatites have been described in Madagascar (Lacroix 1922), Malawi (Martin

et al. 2008), Namibia (Bezing et al. 2008), Ethiopia (Kuster et al. 2009), between Ethiopia, Djibuti,

and Somaliland at Hargeysa in the Mohlileh Hill region (Thoresen and Harrell 2010); Sinai

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Peninsula (Katzir et al. 2006), between Jordan and Saudi Arabia (Bar-Yosef Mayer and Porat 2008;

Wright et al. 2008), the western coast of the Red Sea in Egypt (Harrell and Osman 2007; Kuster

2009; Harrell 2012), in the Tibesti of southern Libya (Monod 1948), Adrar des Iforas in Mali (Ba et

al. 1985), along the Hoggar Massif in Algeria (Ghuma and Rogers 1978; Vianello 1985; Balzi et al.

1997), in Sudan in the region of Jebel Nuhud and at Kadugli, at Buruku in Nigeria (Obaje 2009),

and in the Pare Hills of Tanzania (Thoresen and Harrell 2010). Microcline-bearing pegmatites also

exist within the several peralkaline complexes of North Africa including the Jebel Uweinat and

Jebel Arkenu in south-eastern Libya (Flinn et al. 1991), but amazonite has never been observed at

these sites.

References

ARKELL, A.J. 1953. Shaheinab. Oxford: Oxford University Press.

– 1964. Wanyanga and an archaeological reconnaissance of the south-west Libyan desert. Oxford:

Oxford University Press.

BA, H., R. BLACK, B. BENZIANE, D. DIOMBANA, J. HASCOET-FENDER, B. BONIN, J. FABRE & J.P.

LIÉGEOIS. 1985. La province des complexes annulaires alcalins sursaturés de l'Adrar des Iforas,

Mali. Journal of African Earth Sciences 3: 123–42.

BALZI, S., S. VANNUCCI, O. VASELLI & M. SOZZI. 1997. Contributo alla conoscenza

dell’amazzonite: studio mineralogico-petrografico e geochimico di elementi di monili neolitici e di

esemplari naturali. Minerographica et Petrographica Acta XL: 357–71.

BAR-YOSEF MAYER, D.E. & N. PORAT. 2008. Green stone beads at the dawn of agriculture.

Proceedings of the National Academy of Sciences of the United States of America 105(25): 8548–

51. https://doi.org/10.1073/pnas.0709931105

BEZING, L., R. VON BODE & S. JAHN. 2008. Namibia minerals and localities. Haltern: Edition

Schloss Freudenstein, Bode Verlag GmbH.

CANEVA, I. (ed.). 1988. El Geili. The history of a Middle Nile environment 7000 B.C.–A.D. 1500.

Oxford: Archaeopress.

CARANNANTE, A. 2012. The archaeomalacological remains, in A. Manzo (ed.) Italian

archaeological expedition to the eastern Sudan of the University of Naples ‘L’Orientale’: 93–98.

Napoli: Università degli studi di Napoli ‘L’Orientale’.

ČERNÝ, P. & S. ERCIT. 2005. The classification of granitic pegmatites revisited. Canadian

Mineralogist 43: 2005–26. https://doi.org/10.2113/gscanmin.43.6.2005

DEER, W.A., R.A. HOWI, & J. ZUSSMAN. 1992. An introduction to the rock-forming minerals (2nd

edition). Harlow: Pearson Education Limited.

7

FERNÁNDEZ, V.M., A. JIMENO, M. MENÉNDEZ & J. LARIO. 2003. Archaeological survey in the Blue

Nile area, Central Sudan. Complutum 14: 201–72.

FLINN, D., S. LAGHA, M.P. ATHERTON & R.A. CLIFF. 1991. The rock-forming minerals of the Jabal

Arknu and Jabal Awaynat alkaline ring complexes of SE Libya, in M.J. Salem, M.T. Busrewil &

A.M. Ben Ashour (ed.) The geology of Libya. Volume VII: 2539–58. Amsterdam: Elsevier.

FUHRMAN, M.L. & D.H. LINDSLEY. 1988. Ternary-feldspar modelling and thermometry. American

Mineralogist 73: 201–15.

FULLER, D.Q. 2004. The central Amri to Kirbekan survey. A preliminary report on excavations and

survey 2003–04. Sudan & Nubia 8: 4–10.

GHUMA, M. & J.J.W. ROGERS. 1978. Geology, geochemistry, and tectonic setting of the Ben

Ghnema batholith, Tibesti massif, southern Libya. Geological Society of America Bulletin 9: 1351–

58.

HARRELL, J.A. 2012. Gems from the Red Sea land. The Pegmatite LXVI(3): 15–21.

HARRELL, J.A. & A.F. OSMAN. 2007. Ancient amazonite quarries in the Eastern Desert. Egyptian

Archaeology 30: 26–28.

HOFMEISTER, A.M. & G.R. ROSSMAN. 1985. A spectroscopic study of irradiation coloring of

amazonite: structurally hydrous, Pb-bearing feldspar. American Mineralogist 70: 794–804.

HONEGGER, M. 2004. Settlement and cemeteries of the Mesolithic and Early Neolithic at el-Barga

(Kerma region). Sudan & Nubia 8: 27–32.

– 2005. Kerma et les débuts du nèolithique africain. Genava LIII: 239–49.

KATZIR, Y., M. EYAL, B.A. LITVINOVSKY, B.M. JAHN, A.N. ZANVILEVICH, J.W. VALLEY, Y. BEERI,

I. PELLY & E. SHIMSHILASHVILI. 2006. Petrogenesis of A-type granites and origin of vertical zoning

in the Katharina pluton, Gebel Mussa (Mt. Moses) area, Sinai, Egypt. Lithos 95: 208–28.

KOBUSIEWICZ, M., J. KABACINSKI, R. SCHILD, J.D. IRISH, M.C. GATTO & F. WENDORF (ed.). 2010.

Gebel Ramlah. Final Neolithic cemeteries from the Western Desert of Egypt. Poznań: Poznań

Archaeological Museum.

KRZYŻANIAK, A. 2011. Neolithic cemetery, in M. Chłodnicki, M. Kobusiewicz & K. Kroeper (ed.)

The Lech Krzyżaniak excavations in the Sudan. Kadero: 57–197. Poznán: Poznán Archaeological

Museum.

KURZAWSKA, A. 2010. Mollusc shells at Gebel Ramlah, in M. Kobusiewicz, J. Kabaciński, R.

Schild, J.D. Irish, M.C. Gatto & F. Wendorf (ed.) Gebel Ramlah. Final Neolithic cemeteries from

the Western Desert of Egypt: 227–37. Poznań: Poznań Archaeological Museum.

KÜSTER, D. 2009. Granitoid-hosted Ta mineralization in the Arabian–Nubian Shield: Ore deposit

types, tectono-metallogenetic setting and petrogenetic framework. Ore Geology Reviews 35: 68–86.

8

KÜSTER, D., R.L. ROMER, D. TOLESSA, D. ZERIHUN, K. BHEEMALINGESWARA, F. MELCHER & T.

OBERTHÜR. 2009. The Kenticha rare-element pegmatite, Ethiopia: internal differentiation, U–Pb

age and Ta mineralization. Mineralium Deposita 44: 723–50.

LACROIX, A. 1922. Mineralogie de Madagascar, Tome I. Géologie-Minéralogie descriptive. Paris:

Challamel.

MARTIN, R.F. & C. DE VITO. 2005. The patterns of enrichment in felsic pegmatites ultimately

depend on tectonic setting. Canadian Mineralogist 43(6): 2027–48.

MARTIN, R.F., C. DE VITO & F. PEZZOTTA. 2008. Why is amazonitic K-feldspar an earmark of

NYF-type granitic pegmatites? Clues from hybrid pegmatites in Madagascar. American

Mineralogist 93(2-3): 263–69. https://doi.org/10.2138/am.2008.2595

MONOD, T. 1948. Reconaissence au Dohone, in M. Dalloni & T. Monod (ed.) Mission Scientifique

du Fezzan (1944-1945). Deuxième Partie: 126–56. Alger: Institut de Recherches Sahariennes de

l’Université d’Alger.

OBAJE, N.G. 2009. Geology and mineral resources of Nigeria. Lecture notes 31 in Earth Sciences

120. Berlin: Springer-Verlag.

PERESSINOTTO, D., A. SCHMITT, Y. LECOINTE, R. POURIEL & F. GEUS. 2004. Neolithic nomads at El

Multaga, Upper Nubia, Sudan. Antiquity 98: 54–60. https://doi.org/10.1017/S0003598X00092929

REINOLD, J. 1982. Le site préhistorique d’El-Kadada (Soudan central). La nécropole. Unpublished

PhD dissertation, Université de Lille III.

– 2000. Archéologie au Soudan. Les civilisation de Nubie. Paris: Editions Errance.

– 2005. Note sur le monde animal dans le funéraire néolithique du Soudan. Revue de Paléobiologie

10: 107–19.

– 2007. La nécropole Néolithique d’el-Kadada au Soudan central. Volume I. Les cimetières A et B

(NE-36-O/3-V-2 et NE-36-O/3-V-3) du kôm principal. Paris: Éditions Recherches sur les

Civilisations.

SALVATORI, S. & D. USAI. 2008b. Bright and colourful: the jewellery of R12, in S. Salvatori & D.

Usai (ed.) A Neolithic cemetery in the Northern Dongola Reach (Sudan): excavation at site R12:

21–31. London: Sudan Archaeological Research Society.

SALVATORI, S., D. USAI & Y. LECOINTE (ed.). 2016. Ghaba: an Early Neolithic cemetery in central

Sudan. Frankfurt: Africa Magna.

SIMMONS, W., K.L. WEBBER, A.U. FALSTER & F.W. NIZAMOFF. 2003. Pegmatology – pegmatite

mineralogy, petrology and petrogenesis. New Orleans (LA): Rubellite Press.

THORESEN, L. & J.A. HARRELL. 2010. Archaeogemmology of amazonite, in R. Merk (ed.) The John

Sinkankas gem feldspars symposium. Proceedings of The Sinkankas gem feldspars symposium,

9

Gemological Institute of America, Carlsbad, California, April 17, 2010: 59–62). San Diego: Merk’s

Jade.

VIANELLO, F. 1985. La lavorazione dell’amazonite in Wadi Hafir. Giordania Meridionale. Studi per

l’Ecologia del Quaternario 7: 77–121.

WISE, M.A. 1999. Characterization and classification of NYF-type pegmatites. The Canadian

Mineralogist 37(3): 802–3.

WRIGHT, K.I., P. CRITCHLEY & A. GARRARD. 2008. Stone bead technologies and early craft

specialization: insights from two Neolithic sites in eastern Jordan. Levant 40: 131–65.

ZERBONI, A. & P. VIGNOLA. 2013. Green stone beads from the excavation in Fewet, in L. Mori (ed.)

Life and death of a rural village in Garamantian times. Archaeological investigations in the Fewet

oasis (Libyan Sahara) (Arid Zone Archaeology Monographs, 6): 157–68. Firenze: Edizioni

all’Insegna del Giglio.

ZERBONI, A., P. VIGNOLA, M.C. GATTO, A. RISPLENDENTE & L. MORI. 2017. Looking for the

Garamantian emerald: reconsidering the green-coloured stone beads trade in the ancient Sahara. The

Canadian Mineralogist 55(4): 651–68. https://doi.org/10.3749/canmin.1600052

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Table S1. Averaged WDS electron-microprobe analyses of amazonite samples.

wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma wt% sigma

SiO2 (wt%) ##### 0.08 ##### 0.22 ##### 0.21 ##### 0.29 ##### 0.36 ##### 0.20 ##### 0.37 65.27 0.35 64.9 0.33 64.93 0.25 ##### 0.28 64.5 0.39 ##### 0.22 ##### 0.23 ##### 0.16 ##### 0.17 ##### 0.26 64.7 0.26 65.3 0.18 65.62 0.17 64.96 0.24 64.85 0.20 65.50 0.41 ##### 0.39 ##### 0.47 65.72 0.48 65.95 0.34

Al2O3 ##### 0.14 ##### 0.13 ##### 0.11 ##### 0.09 ##### 0.11 ##### 0.10 ##### 0.11 18.6 0.11 18.7 0.12 18.68 0.15 ##### 0.08 18.8 0.11 ##### 0.11 ##### 0.15 ##### 0.11 ##### 0.18 ##### 0.08 18.8 0.06 18.7 0.12 18.69 0.13 18.82 0.09 18.85 0.12 18.54 0.11 ##### 0.15 ##### 0.22 18.42 0.14 18.44 0.22

FeO 0.00 0.01 0.02 0.02 0.02 0.02 0.03 0.02 0.07 0.02 0.04 0.03 0.06 0.03 0.09 0.02 0.02 0.02 0.02 0.02 0.03 0.03 0.03 0.02 0.02 0.02 0.01 0.02 0.02 0.01 0.03 0.03 0.03 0.02 0.03 0.02 0.02 0.03 0.01 0.01 0.01 0.01 0.02 0.02 0.03 0.02 0.03 0.01 0.02 0.02 0.03 0.02 0.03 0.01

MnO 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.02 0.00 0.01 0.01 0.02 0.01 0.02 0.01 0.01 0.02 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.00 0.01 0.01 0.02 0.01 0.01 0.01 0.01 0.01 0.01 0.02 0.02 0.01 0.02 0.01 0.01 0.01 0.01 0.02 0.02 0.01 0.01 0.02 0.03 0.01 0.01 0.01 0.01

MgO 0.00 0.00 0.01 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.01 0.01 0.00 0.01 0 0.01 0 0 0 0 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0 0.00 0 0.01 — — — — — — — — 0.01 0.01

CaO 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0 0.00 0.01 0.00 0.01 0.01 0.01 0.00 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.00 0.01

Na2O 0.55 0.14 0.39 0.05 0.41 0.16 0.41 0.07 0.33 0.10 0.34 0.06 0.32 0.08 0.63 0.47 0.35 0.11 0.3 0.18 0.37 0.10 0.35 0.13 0.41 0.06 0.33 0.04 0.35 0.04 0.41 0.28 0.29 0.05 0.26 0.03 0.5 0.04 0.56 0.07 0.52 0.05 0.49 0.05 0.55 0.04 0.57 0.06 0.55 0.06 0.53 0.06 0.58 0.07

K2O ##### 0.21 ##### 0.06 ##### 0.24 ##### 0.14 ##### 0.12 ##### 0.12 ##### 0.09 15.41 0.73 ##### 0.13 16.26 0.32 ##### 0.21 ##### 0.24 ##### 0.12 ##### 0.08 ##### 0.05 ##### 0.39 ##### 0.12 ##### 0.08 15.86 0.13 15.80 0.12 15.90 0.11 15.88 0.10 15.66 0.12 ##### 0.21 ##### 0.11 15.50 0.12 15.40 0.14

Total ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ##### ###### 100.70 ###### ##### ##### ##### ##### ###### #####

Si (apfu) ##### ##### ##### ##### ##### ##### ##### 3.017 ##### 2.998 ##### ##### ##### ##### ##### ##### ##### ##### 3.007 3.012 2.995 2.994 3.021 ##### ##### 3.035 3.039

Al ##### ##### ##### ##### ##### ##### ##### 1.013 ##### 1.017 ##### ##### ##### ##### ##### ##### ##### ##### 1.015 1.011 1.023 1.026 1.007 ##### ##### 1.003 1.001

Fe2+ ##### ##### ##### ##### ##### ##### ##### 0.004 ##### 0.001 ##### ##### ##### ##### ##### ##### ##### ##### 0.001 0.000 0.000 0.001 0.001 ##### ##### 0.001 0.001

Mn ##### ##### ##### ##### ##### ##### ##### 0.000 ##### 0.000 ##### ##### ##### ##### ##### ##### ##### ##### 0.001 0.000 0.000 0.000 0.001 ##### ##### 0.000 0.000

Mg ##### ##### ##### ##### ##### ##### ##### 0.000 ##### 0.000 ##### ##### ##### ##### ##### ##### ##### ##### 0.001 0.001 0.000 0.000 — — — — 0.001

Ca ##### ##### ##### ##### ##### ##### ##### 0.000 ##### 0.000 ##### ##### ##### ##### ##### ##### ##### ##### 0.000 0.000 0.000 0.000 0.001 ##### ##### 0.001 0.000

Na ##### ##### ##### ##### ##### ##### ##### 0.057 ##### 0.027 ##### ##### ##### ##### ##### ##### ##### ##### 0.045 0.050 0.047 0.044 0.049 ##### ##### 0.048 0.052

K ##### ##### ##### ##### ##### ##### ##### 0.909 ##### 0.958 ##### ##### ##### ##### ##### ##### ##### ##### 0.932 0.925 0.935 0.935 0.921 ##### ##### 0.913 0.905

Orthoclase 0.95 0.96 0.96 0.96 0.97 0.97 0.97 0.941 0.97 0.973 0.97 0.97 0.96 0.97 0.97 0.96 0.97 0.98 0.95 0.95 0.95 0.96 0.95 0.95 0.95 0.95 0.95

Albite 0.05 0.04 0.04 0.04 0.03 0.03 0.03 0.059 0.03 0.027 0.04 0.03 0.04 0.03 0.03 0.04 0.03 0.03 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05

Anorthite 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 0 0 0.00 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

Pb ppm 960 0.06 612 0.03 894 0.05 903 0.02 478 0.03 428 0.02 261 0.02 426 0.04 321 0.03 249 0.03 207 0.04 364 0.02 288 0.02 654 0.04 872 0.02 266 0.03 918 0.03 1368 0.02 472 0.03 575 0.03 407 0.03 464 0.05 663 0.07 547 0.03 555 0.05 731 0.06 547 0.06

Sr 392 0.06 146 0.03 241 0.03 180 0.03 234 0.04 172 0.03 45 0.01 172 0.03 310 0.04 235 0.05 748 0.08 178 0.03 249 0.03 114 0.02 266 0.05 91 0.01 264 0.04 262 0.03 287 0.04 121 0.03 289 0.06 286 0.04 299 0.05 204 0.03 339 0.06 338 0.06 325 0.06

Cs 26 0.02 224 0.02 248 0.02 146 0.01 326 0.03 260 0.03 94 0.01 117 0.01 181 0.01 46 0.01 91 0.01 130 0.02 80 0.01 1552 0.04 364 0.03 364 0.02 870 0.03 683 0.03 117 0.02 209 0.02 23 0.00 62 0.01 39 0.01 308 0.03 181 0.02 203 0.03 52 0.01

Ba 267 0.03 37 0.01 250 0.05 46 0.01 222 0.02 148 0.02 351 0.03 281 0.04 162 0.03 631 0.05 2515 0.26 197 0.03 105 0.01 162 0.03 21 0.00 76 0.01 485 0.04 64 0.01 178 0.02 203 0.03 80 0.02 49 0.01 292 0.04 419 0.05 285 0.04 206 0.03 341 0.05

Rb 6284 0.04 6057 0.05 7279 0.09 5922 0.03 1538 0.02 1362 0.02 959 0.02 5529 0.04 5450 0.07 1460 0.09 1189 0.08 2090 0.03 4022 0.03 7908 0.07 7320 0.03 5162 0.05 7940 0.06 9877 0.05 2177 0.03 2041 0.02 1949 0.03 2326 0.03 1899 0.02 2247 0.04 2153 0.03 2087 0.04 2085 0.04

K/Rb 20 22 18 22 87 98 139 23 24 92 110 64 33 16 18 26 17 13 60 64 68 57 68 57 59 62 61

Ancient and ethnographic comparison beadsRaw material outcrops Neolithic beads from R12 cemetery (Sudan)

R12eEghei Zuma

a, Libya

Eghei Zuma

b, Libya

Eghei Zuma

c, Libya

Kenticha,

EthiopiaMauritania

Talat Umm,

Jaraf, Egypt

Jebel

Hafafit,

Egypt

Jebel Migif,

Egypt

Eghei Zuma

d, Libya

Konso b,

Ethiopia

Eastern

Jordan

Konso a,

Ethiopia

Empirical formula normalized on the basis of 5 cations

End-members

Minor elements

R12f R12g R12h R12iR12c R12dMali e R12aMali c R12bMali a Mali b

Jebel

Nuhud,

Sudan

Mali d

11

Table S2. Exotic materials recorded at Nubian Early Neolithic (El Barga), Nubian Middle Neolithic (J. Ramlah, Kadruka and R12) and

Early Neolithic sites in central Sudan (Ghaba and Kadero). ND: exotic material present, but quantity of pieces not determined. Greyed

boxes highlight the presence of specific items.

Site Location Exotic shells References

Conus

sp.

Glycymeris

pectunculus

Cypraea

sp.

Nerita

sp.

Lambis

truncata

sebae

Engina

mendicaria

J. Ramlah E-01-

2

Egypt 1 53 22 Kurzawska 2010

J. Ramlah E-03-

1

Egypt 1 Kurzawska 2010

J. Ramlah E-03-

2

Egypt 1 4 3 Kurzawska 2010

El Barga North Sudan ND ND ND ND Honegger 2004, 2005

Kadruka 1 North Sudan ND >43 Reinold 2005

R12 North Sudan 1 24 Salvatori & Usai

2008b

Ghaba Central

Sudan

4 17 Salvatori et al. 2016

Kadero Central

Sudan

20 1474 Krzyżaniak 2011

Site Location Exotic stones References

12

Amazonite beads

pendants

Amazonite

lumps

Turquoise Malachite splinters

and

powder

J. Ramlah E-01-

2

Egypt 1 ND Kobusiewicz et al.

2010

J. Ramlah E-03-

1

Egypt ND Kobusiewicz et al.

2010

J. Ramlah E-03-

2

Egypt 4 ND Kobusiewicz et al.

2010

El Barga North Sudan ND Honegger 2004

Kadruka 1 North Sudan ND ND Reinold 2000, 2005

Kadruka 21 North Sudan 3 pendants+ND

beads

Reinold 2000

R12 North Sudan 587 23 >50 splinters+powder

in 3 graves

Salvatori & Usai

2008b

Umm Melyekta North Sudan ND Fuller 2004

Multaga North Sudan ND Peressinotto et al.

2004

Ghaba Central

Sudan

>276 splinters+

powder in 64 graves

Salvatori et al. 2016

Kadero Central

Sudan

2 1 26 Krzyżaniak 2011

13

Table S3. Exotic materials recorded at Late Neolithic sites in central and eastern Sudan. ND: exotic material present, but the quantity of

pieces not determined.

Site Location Exotic shells References

Conus

sp.

Glycymeris

pectunculus

Cypraea

sp.

Nerita

sp.

Lambis

truncata sebae

Engina

mendicaria

Kadada A & B Central

Sudan

1 5 2 Reinold 2007

Kadada C Central

Sudan

4 54 Reinold 1982

Shaheinab Central

Sudan

1 30 4 Arkell 1953

UA53 Kassala East Sudan ND Carannante 2012

Site Location Exotic stones References

Amazonite beads

pendants

Amazonite

lumps

Turquoise Malachite splinters

powder

Shaheinab Central

Sudan

9 165 Arkell 1953

Kadada A & B Central

Sudan

444 20 Reinold 2007

Kadada C Central

Sudan

5 1 6 Reinold 1982

14

Geili Central

Sudan

ND Caneva 1988

Rabob Central

Sudan

ND Fernandez et al.

2003