Southern African Humanities
Vol. 21
Pages 239–261
Pietermaritzburg December, 2009
A cache of ~5000 glass beads from the Sibudu Cave
Iron Age occupation
Marilee Wood, 2Laure Dussubieux and 1,3Lyn Wadley
1
School of Geography, Archaeology & Environmental Studies, University of the
Witwatersrand, Wits, 2050 South Africa; [email protected]
2
Field Museum, Department of Anthropology, 1400 S. Lake Shore Drive,
Chicago, IL 60605; [email protected]
3
Institute for Human Evolution, University of the Witwatersrand;
[email protected]
1
ABSTRACT
A cache of ~5000 glass beads was recovered from a small pit in an Iron Age layer at Sibudu Cave. The
bead strings incorporated brownish-red, blue-green, blue and other colours of glass beads, some copper
beads and also two perforated Conus ebraeus shells. A necklace of shell disc-beads interspersed with blue
glass beads was also present. Sixteen of the glass beads were analysed chemically using LA-ICP-MS at
the Field Museum, Chicago. The results indicate the beads originated in India. The Iron Age layers have
calibrated radiocarbon dates between AD 1020 and 1160 and they incorporate Blackburn facies ceramics.
These Blackburn associations seem too early for the types of beads represented and the cache of beads may
have been hidden in the shelter in the 1500s or 1600s after the Blackburn occupation.
KEY WORDS: Sibudu Cave, Iron Age, glass beads, chemical analysis, Indian beads.
Sibudu is a large rock shelter located approximately 40 km north of Durban, South
Africa, about 15 km inland from the Indian Ocean, on a steep cliff overlooking the
Tongati River. The shelter is 55 m long and about 18 m in breadth. Entering the shelter
necessitates crossing the river (which is sometimes shoulder-deep) and scaling a 3 m
rock face. There are sufficient hand-holds and natural steps to make entry and exit
relatively easy for a sound-bodied person with a good head for heights, but it would
not be possible to get cattle into the shelter. The point about access is made only to call
attention to the atypical nature of the shelter for Iron Age settlement.
The excavation grid is in the northern part of the shelter approximately 100 m above
mean sea-level. A small trial trench roughly 1 m deep was excavated in 1983 by Aron
Mazel and his stratigraphic names for the Iron Age layers, recorded in notes housed
in the Natal Museum, have been retained here. The present excavations, which are
ongoing, began in 1998 and Middle Stone Age (MSA) deposit over 21 m2 and Iron
Age deposit over 26 m2 have been excavated by the Wadley team (Wadley & Jacobs
2004, 2006). Each metre square is divided into quadrants a (north-east), b (south-east),
c (north-west) and d (south-west) and all artefacts are excavated and bagged separately
from each quadrant.
The uppermost occupation is from the Iron Age and directly below this is the MSA
with a long and detailed cultural sequence. No Later Stone Age (LSA) remains are present
in Sibudu and it seems that a long hiatus occurred between the final MSA occupations
and the first Iron Age occupations. This hiatus is not detectable as a sterile unit in the
stratigraphy. Today the surface of the cave floor is scoured by wind in late winter/early
summer and similar circumstances in the past may have prevented the accumulation
of sterile deposits.
http://www.sahumanities.org.za
239
240
Southern AFRICAN humanities, vol. 21, 2009
The stratigraphy relevant to the Iron Age of the site comprises three layers. Below
the surface sweep of modern dust and leaf litter is brown silt with vegetal material
(BSV). The underlying brown sand with stones (BSS), which is deep in parts of the
site, has been arbitrarily divided and the lower part of the layer is named BSS2. Three
radiocarbon ages have been obtained from charcoal (Table 1). The calibrated dates
suggest that essentially the same age is represented throughout the Iron Age occupation;
this issue is discussed again later.
Layers BSV, BSS and BSS2 contain ceramics, upper and lower grindstones, rare
pieces of metal, bones, seeds, gourd fragments, wood, wooden stakes, a wooden digging
stick and even some fragments of basketry. The ceramics are largely undecorated, with
the exception of a few sherds with simple, incised parallel lines. The sparse decoration,
together with the shapes of some rim fragments, suggests that the ceramics belong
to the Blackburn facies of the local Late Iron Age sequence (Whitelaw pers. comm.;
Huffman 2004, 2007). Blackburn sites have calibrated radiocarbon dates between about
AD 1100 and 1300, but the facies may extend to about AD 1500 (Huffman 2004, 2007:
444). The name site, Blackburn (Davies 1971), has a calibrated age (all calibrations in
this paper use the curve from Vogel et al. 1993) of AD 1170–1235 (Huffman 2004),
while Mpambanyoni (Robey 1980) has calibrated ages between AD 1025 and 1250
(Huffman 2004).
At Sibudu, the remains of a clay hut floor were found in the southern part of the
excavation grid. The full extent of the floor has not been excavated, but on present
evidence, the floor is likely to be about the size (~5 m across) of the ones uncovered at
Blackburn, where they would have been used as foundations for Nguni-style beehive
huts (Davies 1971). A beehive hut is also likely to have been placed above the clay
floor at Sibudu. The Sibudu floor is unburnt and no more than about two centimetres
thick, so it is more like a temporary smear than a permanent hut floor. Trampled grass
that may have served as matting was near the clay floor. Several Iron Age pits (some of
which were greater than a metre in diameter) were dug into the MSA deposits, creating
a mixture of MSA and Iron Age material culture, food waste, ashy deposit and charcoal.
The pits became refuse dumps, though they may originally have had another purpose.
One pit had wooden pegs surrounding it, suggesting that a leather cover might have been
staked over it. However, none of the pits was lined with dung or had any other indication
of use, such as food storage. Similar pits were found at Blackburn (Davies 1971) and
at even earlier sites, such as the Early Iron Age site of Msuluzi Confluence (Maggs
1980a). The Sibudu pits contained a great many well-preserved, uncarbonized seeds
from a variety of edible fruits, including Sclerocarya birrea (marula) and Harpephyllum
caffrum (sour plum) (Sievers Scott 2005). Some of the seeds were gnawed by rodents,
which probably feasted on the refuse in the pits.
TABLE 1
Sibudu Iron Age radiocarbon ages (from charcoal). Calibrated ranges rounded off to the nearest 10.
Lab. No.
Sample designation
δ13C
(‰PDB)
Radiocarbon
years b.p.
Calibrated 1 sigma range
Pta-8015
Pta-9202
Pta-9196
Square E3d, BSS pit
Square F5a, hut floor
Square B5c, BSS2
-22.3
-27.3
960 ± 25
970 ± 50
1030 ± 40
1040–1170
1030–1180
1010–1040
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
241
Fig. 1. Intact Sibudu bead cache: front.
A cache of over 5000 glass beads comprising many coiled strands (Figs 1 & 2) was
found in a small hole that was deliberately dug into B4b (the south-east quadrant of
square B4) from layer BSV into BSS. The bead coils fitted the shape of the hole perfectly
and they may have been stored in a bag, though no trace of one preserved. The thongs
or twine that originally held the beads had decayed so the neat lines of beads were no
longer securely connected where they lay amongst some loose beads in the hole. Most
beads were brownish-red, though blue-green and blue beads formed a design amongst
the brownish-red ones. A few crimped copper beads (four whole and four fragments)
Fig. 2. Intact Sibudu bead cache: back.
242
Southern AFRICAN humanities, vol. 21, 2009
Fig. 3. Conus ebraeus shells with embedded bead.
were found amongst the loose beads, but more are incorporated into the strung beads
along with two perforated Conus ebraeus shells (Fig. 3). These marine shells occur
commonly in warm waters all along the east coast of Africa with the southern limit
around Port St Johns (Richards 1981).
During the excavation of the bead cache, a 10 % solution of Paraloid and acetone was
painted on the coils in an attempt to hold the beads in place. A syringe was used to apply
Paraloid to the coils in the centre of the cache. As far as possible, the strings of beads
were removed in toto, but because the coils formed a substantial chunk more than 10 cm
thick, many loose beads were embedded in the ashy silt and could not be resin-coated.
An entire necklace of putative ostrich eggshell disc-beads that included some blue glass
beads was recovered as part of the cache. The shell disc-bead necklace will be described
elsewhere after analysis by Lucinda Backwell. The disc-beads need careful examination
of the kind undertaken by Ward and Maggs (1988) on examples from KwaZulu-Natal.
They note that disc-beads made from ostrich eggshell and Achatinidae are fairly common
at KwaZulu-Natal Early Iron Age sites, such as Ntshekane, Ndondondwane and Magogo
(Ward & Maggs 1988) and Msuluzi Confluence (Maggs 1980a). Late Iron Age sites in
KwaZulu-Natal, such as Moor Park and Mpambanyoni, seldom contain disc-beads.
Glass beads are far less common in KwaZulu-Natal and are reported in abundance
only from Iron Age sites post-dating 1800 (e.g. Van der Merwe et al. 1989). Early Iron
Age sites contain a few glass beads: one was found at Ntshekane (Maggs & Michael
1976), another at KwaGandaganda (Whitelaw 1994) and a third from a Ntshekane-phase
pit on the bank of the Zinkwazi River (site 2931AB 17). No glass beads were found in
the Late Iron Age sites of Blackburn and Mpambanyoni (Davies 1971; Robey 1980).
In the Thukela Basin, several LSA sites have glass beads of European, but not Indian
origin. Mgede Shelter yielded a pale yellow glass bead as well as green, white, and
bi-coloured red and white glass beads (Mazel 1986a: 377). Mbabane Shelter produced
six red glass beads with black centres and eSinhlonhlweni Shelter one blue glass bead
with a white centre (Mazel 1986b: 410). Twenty glass beads found in KwaThwaleyakhe
Shelter and seven in Maqonqo Shelter are thought to have been of Italian origin (Mazel
1993: 20, 1996: 25). This sparse glass bead distribution at Iron Age and LSA settlements
in KwaZulu-Natal emphasizes the rarity and importance of the Sibudu bead cache.
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
243
PREPARATION AND CLASSIFICATION OF THE BEAD ASSEMBLAGE
The glass bead cache was cleaned in the laboratory and deposit not secured with resin
was sieved through 1 mm mesh to recover loose beads. The Paraloid coating has been
kept on the solid lump of coiled beads, but this coating can be removed with acetone if
this is considered necessary in the future. All measurements and numbers in the tables
refer to the 2480 loose beads only, because the beads in the consolidated coils cannot be
counted or measured. The number of consolidated beads has, however, been estimated
at around 2700. This number was arrived at by weighing the 1607 small sized brownishred beads then comparing that weight to the consolidated mass (it was estimated that
10 % of the mass was matrix so 10 % of the mass was subtracted before calculating
the number of beads).
Classifying glass beads
Several characteristics, including method of manufacture, end treatment, structure, shape,
size, colour and translucency are used to classify beads. This classification draws on
Kidd and Kidd (1970), Karklins (1985: 85–117) and Wood (2005: 23–38).
All Sibudu glass beads are simple in structure, meaning they are made of a single
undecorated layer of glass. All are drawn, that is, they were cut into lengths from glass
tubes that were drawn or pulled out from a gather (globule) of molten glass that had
been perforated through the centre. The perforation remains intact in the drawing process
and becomes the hole in the centre of each bead. Once cut into lengths the bead ends
are often heat treated (rounded) by packing them into a large pan with ash or another
medium to keep them separated. They are then reheated until the glass begins to melt,
smoothing or rounding the cut ends. The longer the reheating process, the rounder the
beads become, but care must be taken to avoid over-melting or they will collapse and
be ruined. The ends of most tubular Sibudu beads show little evidence of rounding, but
they are smooth (that is, not sharp) indicating they were reheated only briefly.
The Sibudu beads can be divided into three shapes: tube, cylinder and oblate. Most
cataloguing systems do not distinguish between tubes and cylinders, but Wood has found
it useful in classifying pre-European bead assemblages. The bodies of tubular beads have
straight, parallel sides. Their ends may be slightly smoothed through reheating, but the
profile remains straight. The ends of cylindrical beads are visibly rounded, but a small
portion of the body can remain straight. Most irregularly shaped beads fall into this
category. Oblate beads have been reheated to the point that the entire body is smoothly
rounded. Their length must be less than their diameter (if they were equal the bead would
be a sphere). The oblate designation is reserved for uniform, well-formed beads.
Bead sizes are made up of two measurements: first the diameter, perpendicular to the
perforation, is measured (Table 2) and then the length, parallel to the perforation. The
TABLE 2
Size range parameters for Sibudu beads.
Size range
Diameter in mm
minute
small
medium
large
< 2.5
2.5–3.5
3.5–4.5
> 4.5
244
Southern AFRICAN humanities, vol. 21, 2009
TABLE 3
Length ratio parameters for Sibudu beads.
Length ratio designations
disc
Formula
short
length = > 1/ 5 and < 4/ 5 diameter
standard
long
very long
length = < 1/ 5 diameter
length = > 4/ 5 and < 1 1/ 5 diameter
length = > 1 1/ 5 and < 2 diameter
length = > 2 diameter
size ranges (diameter measurements) have been developed for use with southern African
glass bead assemblages (Wood 2005: 33) because bead diameters there are smaller than
those found in most other regions, such as the East African coast (Chittick 1974: 464;
Morrison 1984: 182). Bead lengths are recorded as length-ratio (Table 3), which is the
relationship between the length and diameter of the bead. These categories are adapted
from Chittick (1974: 463).
Bead colours are determined using the Munsell Book of Colours (Munsell 1976) under
natural daylight. Bead researchers normally restrict glass translucency (or diaphaneity)
descriptions to three categories: transparent, translucent and opaque. Wood has found
that gradations between these categories can be useful when working with assemblages
of small, monochrome drawn beads. Therefore the categories of transparent-translucent,
translucent-transparent, translucent-opaque and opaque-translucent have been added to
the normal three (Wood 2005: 35).
Fig. 4. Brownish-red loose Sibudu beads in three size groups.
245
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
Fig. 5. Green, yellow, blue and blue-green loose Sibudu beads.
Classifying the Sibudu glass beads
As mentioned earlier, these data (Appendix 1) include only the 2480 loose beads (Figs 4
& 5), not those in the consolidated strings. Table 4 records their shapes and end treatment.
Table 5 demonstrates that most Sibudu beads are small and short and that very few fall
outside the boundaries of small to minute and short to standard categories. Table 6 lists
colour groups and translucency for the beads. As is evident, brownish-red beads (Fig. 4)
form the bulk of the assemblage. Blue-green and blue (Fig. 5) are the only other colours
represented by more than a few beads. Any blue with even a touch of green is placed
into the blue-green category. The designation ‘blue’ is reserved for cobalt blue beads.
Chemical analysis shows that cobalt colours the blue beads and copper (sometimes with
the addition of iron) colours the blue-green ones.
CHEMICAL ANALYSIS OF THE BEAD ASSEMBLAGE1
Method
The analyses carried out at the Field Museum, Chicago, involved a Varian inductively
coupled plasma-mass spectrometer (ICP-MS) and a New Wave UP213 laser, for direct
TABLE 4
Shape and end treatment of Sibudu loose glass beads.
Shape
tube
cylinder
oblate
total
Number
2425
54
1
2480
Heat rounded
77
54
1
132
Lightly reheated
2348
2348
246
Southern AFRICAN humanities, vol. 21, 2009
TABLE 5
Size ranges and length ratios of Sibudu loose glass beads.
Size range
Length ratio
Standard
114
434
16
-
Short
332
1370
196
2
minute
small
medium
large
Long
2
14
-
Total
448
1818
212
2
introduction of solid samples. The parameters for ICP-MS were optimized to ensure a
stable signal with a maximum intensity over the full range of masses of the elements
and to minimize oxides and double ionized species formation (CeO+/Ce+ and Ba++/Ba+
< 1–2 %). For that purpose the argon flows, the radio-frequency power, the torch
position, the lenses, the mirror and the detector voltages were adjusted using an autooptimization procedure. For better sensitivity, helium is used as a gas carrier in the
laser. A single point analysis mode using a laser beam diameter of 55 µm, operating at
70 % of the laser energy (0.2 mJ) and at a pulse frequency of 15 Hz was used in order
to determine elements with concentrations in the range of ppm and below, while leaving
an almost invisible mark on each bead’s surface. A pre-ablation time of 20 seconds was
set up to eliminate the transient part of the signal and to ensure that possible surface
contamination or corrosion did not affect the results. For each glass sample, an average
of four measurements corrected from the blank was used for calculating concentrations.
Isotope 29Si was used for internal standardization. In order to isolate the main components
of the glasses, reduced compositions were calculated by normalizing the seven major
and minor oxides to 100 %. This process removes most of the compositional effects
of additives, such as colourants, and permits examination of the basic glass recipe
(Gratuze 1999).
Two series of standard reference materials were used to determine the concentrations
of major, minor and trace elements. The first series of external standards were NIST
SRM 610 and 612. Both of these standards are soda-lime-silica glass doped with trace
elements in the range of 500 ppm (SRM 610) and 50 ppm (SRM 612). Certified values are
available for a very limited number of elements. Concentrations from Pearce et al. (1997)
were used for the other elements. The second series of standards were manufactured by
Corning. Glasses B and D best match the compositions of ancient glass (Brill 1999: 544).
TABLE 6
Colour groups and translucency of Sibudu loose beads. Tsp = transparent; Tsp/tsl = transparenttranslucent; Tsl/tsp = translucent-transparent; Tsl = translucent; Tsl/op = translucent-opaque; Op/tsl =
opaque-translucent; Op = opaque; Ind = indeterminate.
Colour group
indeterminate
black
blue
blue-green
green
yellow
brownish-red
Tsp
2
-
Tsp/tsl
-
Tsl/tsp
1
-
Tsl
3
3
-
Tsl/op
4
80
128
4
8
-
Op/tsl
6
-
Op
2
2238
Ind
1
-
Total
11
2
80
134
7
8
2238
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
247
Glass Corning C is generally not one of the standards used for quantitative analysis, but
is measured regularly to check the reliability of our results.
The detection limits range from less than 1 ppb to 2 ppm for copper and are
generally under 1 ppm for most of the elements. Accuracy is generally better than
10 %. Reproducibility is better than 10 % for most elements. For more details about the
performance of LA-ICP-MS for glass analysis at the Field Museum, see Dussubieux
et al. (2009).
Results (see Appendix 2)
Ancient glass was generally made by melting sand, which is mostly silica (SiO2), with
a flux (an alkali or alkali earth-based ingredient) added to lower the melting point of the
mix. Sodium-based fluxes were generally obtained either from mineral deposits or from
soda plant ash, the former being purer than the latter. The magnesia (MgO) and in some
cases the potash (K2O) contents of the glass act as indicators of the purity of the soda
flux. For example, glass made with sodium carbonate taken from mineral deposits (also
called natron) contains low levels of magnesia and potash while glass made with soda
plant ash will have concentrations of magnesia and potash higher than 1.5 %. Soda-rich
plants are known as halophytic plants and grow in salt-rich soils. Different proportions
of magnesia, soda and potash may result from the use of different types of halophytic
plants. Saltpetre (potassium nitrate), a mineral efflorescence, provides a rather pure
potash flux while forest plant ash that contains both potash and lime (CaO) results in a
glass with a more mixed composition. Lead can also be used as flux.
Alumina (Al2O3) and lime are necessary to obtain durable glass. They are generally
present in the sand along with silica, although as has been mentioned lime may be
added with certain fluxes. If the concentrations of lime present in the sand and/or flux
are too low, additional amounts may be added separately. Differing proportions of
these elements in a glass, as well as concentrations of iron (Fe), titanium (Ti) and trace
elements, can help point to the sand or rock sources used by the glassmaker. Granite
sand generally produces glass in which proportions of alumina are much higher than
lime, while a lime sand, which may come from a coastal deposit, will result in a glass
in which proportions of lime are higher than alumina. Crushed quartz pebbles, a rather
pure source of silica, produce a glass low in both lime and alumina.
In the glass used to make the Sibudu beads, the main constituent after silica is soda
(~19 %); the low levels of magnesia (~0.8 %) indicate that the soda has a mineral origin.
This type of glass is characterized by relatively high alumina concentrations (higher
than 4 %) due to the addition of granite sand that contains relatively high levels of
impurities and is often called mineral soda alumina (m-Na-Al) glass. Based on trace
element concentrations, two subtypes have been identified for this glass. The first
subtype comprises glass samples mostly from South India, Sri Lanka and Southeast
Asia, which date from the fifth century BC to the tenth century AD. This glass, rare in
Africa, has average uranium concentrations around 20 ppm and relatively high barium
concentrations, up to ~3500 ppm. It is known as low uranium-high barium (lU-hBa)
glass. The second subtype dates from the eighth to the nineteenth centuries and is more
common at sites in sub-Saharan Africa and has been found on the west coast of India
(Dussubieux et al. 2008). Uranium concentrations in this m-Na-Al glass are higher than in
the previous subtype and average approximately 100 ppm, while barium concentrations
248
Southern AFRICAN humanities, vol. 21, 2009
are significantly lower; this subtype is labelled high uranium-low barium (hU-lBa)
glass. This type of glass has been identified in Madagascar (Robertshaw, Rasoarifetra
et al. 2006) as well as at numerous Iron Age sites in southern Africa (Robertshaw et al.
2003; Robertshaw, Wood et al. 2006). The m-Na-Al glass in this study has an average
uranium concentration of 180 ± 80 ppm and an average barium concentration of
320 ± 90 ppm and is therefore part of the hU-lBa sub-group.
Ingredients used to colour the glass samples vary. The two yellow beads (Fig. 6)
contain more lead and tin than other beads, indicating they were coloured with lead
stannate (PbSnO3), a yellow crystalline compound. The cobalt blue glass beads contain
cobalt associated with arsenic and nickel (see Dussubieux et al. 2008 for a discussion
on this colourant). The blue-green beads contain significant quantities of copper oxide
(more than 0.5 %) and vary in hue depending on other additives. When more cobalt is
present they are bluer, and with higher levels of lead stannate they are greener. The green
beads are copper rich and contain elevated levels of lead stannate. They also contain
relatively high quantities of iron (6.1 and 4.3 %), which may have played a role in the
colouring of these artefacts (the one with higher iron content is more olive-green than
the other). The brownish-red glass is coloured with copper; the colour was quite likely
facilitated by the presence of relatively high concentrations of iron (see Dussubieux et
al. 2008 for more details).
Fig. 6. Sibudu test beads L–R: top SBDU 01–04, middle SBDU 05–10, bottom SBDU 11–16.
DISCUSSION
The cache of ~5000 beads, indeed the entire Iron Age occupation at Sibudu, is
extraordinary in several ways. Such wealth in beads might be expected in association
with an elite dwelling, yet the shelter is an unlikely place for this. Iron Age occupation
in shelters is, in any event, atypical other than in defensive situations, for example
during the Mfecane. There presently is no reason to suspect that Sibudu was used
for such purposes. Another possibility is that the shelter was home to a diviner or
herbalist who practiced in this unusual and relatively inaccessible place (Whitelaw
pers. comm.). Clients may have brought gifts or payment for advice and healing. Only
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
249
the Conus ebraeus beads are local if the disc beads prove to be of ostrich eggshell.
Maggs (1980a) considers that eggshell beads came from hunter-gatherers who lived
in country above 1200 m a.s.l. because ostriches apparently are not endemic to coastal
and bushveld environments. The rare copper beads were probably also imported
(Miller & Whitelaw 1994).
Caches of beads, such as the one recovered from Sibudu Cave, are rare; only one
other from pre-European contexts in southern Africa is known to the authors. In it
2600 glass beads were found in a pot on a hut floor at Kgaswe homestead in eastern
Botswana (Denbow 1986: 19). Three calibrated radiocarbon dates placed the site between
AD 1000 and 1260. The beads indicate that a date toward the end of this span is most
likely (Wood 2005: 44). The Sibudu cache is also remarkable because the care taken in
excavating it allows us to see that the beads were strung for wearing. Beads strung for
trade distribution would not be artfully interspersed with different colours (for example,
the two blue-green beads that flank the uncommonly long brownish-red one in Fig. 1),
let alone with marine shells and copper beads. The general uniformity in size and shape
of the beads is also noteworthy.
Origins of the beads
The high alumina sand and mineral soda glass used to make the Sibudu beads suggests
they were probably produced in India. Early historical sources list both Cambay on
India’s west coast and Negapatam (the current spelling is Nagapattinum) on the southeast
coast as ports where Portuguese and subsequent European traders procured beads for the
southern and East African trade. Cambay is mentioned in several early records as a source
of beads for this trade. According to Gaspar Correa’s 1512 account of Cabral’s visit to
Sofala in 1501, two classes of beads were exported from Cambay: red beads (contas
vermellias) and small transparent coloured glass beads (continhas de vidro cristalinas).
In addition it is recorded that small transparent glass beads were taken along as gifts for
“the king” (Theal 1898, II: 26–7). In 1505 Duarte Barbosa stated that Moors from Kilwa,
Mombasa and Malindi brought Cambay cloths and “many small beads, grey, red and
yellow” to Sofala and Angoche in small vessels called zambucos (Dames 1918: 12, 15).
He also described Cambay beads as “one of the important articles of trade brought from
India to the Red Sea and the East Coast of Africa by Mohammedan sea-faring traders”
(Arkell 1936: 299). Tomé Pires (ca. 1511) recorded that “glass beads and other beads
from Cambay” were used in the Indian Ocean trade (Freeman-Grenville 1962: 125).
Axelson (1973: 46) notes that in 1506 the Portuguese at Sofala were fortunate in that a
caravel arrived with “loot from Kilwa” that included beads from Cambay, because the
local inhabitants did not view European ones with favour. Some scholars (Arkell 1936:
300; Francis 2002: 171) contend that beads exported from Cambay, especially the red
ones (the colour of many carnelian beads), were of stone only. Careful reading of early
records indicates that some glass beads were probably exported as well. In addition to
the statements by Cabral and Pires already mentioned, another account by Pires noted
that at Malacca traders from Borneo “take a great deal of coloured glass beads from
Cambay” (Cortesão 1967: 133). If both stone and glass beads were being exported
from Cambay, were they being made there? Stone beads, especially of carnelian and
agate, have been made near or at Cambay for possibly two millennia (Arkell 1936: 304;
Francis 2002: 108–9). Barbosa recorded that Cambay had
250
Southern AFRICAN humanities, vol. 21, 2009
many skilful turners who make … beads of sundry kinds, black, yellow, blue and red and many
other colours … Here too are many workers in stones … A great amount of work is also done here
in coral, alaquequas (carnelians) and other stones (Arkell 1936: 301).
Although the bead colours mentioned by Barbosa could be represented by stone beads
(as Arkell believed), Barbosa’s reference to both turners of coloured beads and “workers
in stones” suggests he might have been saying that both glass and stone beads were
being made in Cambay. However, to date we have found no records of archaeological
or other evidence to suggest that glass or glass beads were actually made there. In sum,
it seem likely that both stone and glass beads were exported from Cambay, but only
stone beads were made there or in the near vicinity.
Negapatam was also mentioned in early Portuguese records as a source of beads.
Several references state that Portuguese traders were obliged to purchase beads at
Negapatum because European beads were not acceptable to local inhabitants (Schofield
1958: 183; Van der Sleen 1956: 28, 1958: 212). Van der Sleen furthermore reports
that when this knowledge reached the Portuguese king, he wrote to “his Governor in
Negapatam, to ensure that his ships could be provided there with the beads [recorded
as green, yellow and blue] wanted by the natives on the African coast” (Van der Sleen
1956: 28). In Lavanha’s account of the survivors of the wrecked Portuguese ship,
Santo Alberto, who walked from just west of the Umtata River inland to Delagoa Bay
in 1593, it was reported that one group of natives wore red beads in their ears. Nuno
Velho Pereira, the chief captain, said he
saw from their [the beads’] appearance that they came from the land of Inhaca, who is king of
the people living by the river of Lourenço Marques. These beads are made of clay of all colours,
of the size of coriander seed. They are made in India at Negapatam, whence they are brought to
Mozambique and thence they reach these negroes through the Portuguese who exchange them for
ivory (Theal 1898, II: 303).
The reference to these beads, especially red ones, as clay (barros miudas) is a common
misidentification because they look like terracotta or earthenware. Although Schofield
maintained (based on the early records) that the beads must have been clay, he had to
admit that “it is a curious fact that none of the clay beads from Negapatam have as yet
been found on an archaeological site” (1938: 369). Even though many tens of thousands
of beads dating to this period have been recovered in eastern and southern Africa since
Schofield made this statement, not a single Indian ‘clay’ bead has been found. Bead
specialists, including Van der Sleen (1958: 212, 1973: 82) and Francis (2002: 226 ff.
34) recognized that these “beads are nothing but opaque glass” (Van der Sleen 1958:
212). Indeed, they are the beads that Van der Sleen dubbed ‘Trade-wind’ and Francis
called ‘Indo-Pacific’.
The Lavanah account is filled with references to glass beads being used during the
survivors’ journey as gifts or to pay for goods and services. It is also recorded that
when they reached the latitude 27°27′, which Schofield (1958: 184) identified as in the
Newcastle-Utrecht district of KwaZulu-Natal, they headed east “in which direction lay
the village where their red beads were sold, which are those which come from the river
of Lourenço Marques” (Theal 1898, II: 333).
Again the question arises: were the beads exported from Negapatam made there?
Van der Sleen (1956: 28) opined that it is unlikely beads were being made there. After
a careful survey of the area in 1988, Francis found no evidence for beadmaking, glass
making or glass working at the site (Francis 2002: 40). So once again we have a port
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
251
through which glass beads were exported, but they were evidently made elsewhere.
An additional informative note about Negapatam is recorded by both Schofield and
Van der Sleen: the port, which had been a Portuguese factory, was taken over by the
Dutch in 1660. After the takeover, the export of beads from Negapatam “either ceased
altogether or could only be carried on as contraband” (Schofield 1938: 366). Further,
Van der Sleen thought that the “importation of Trade-wind beads must have stopped
shortly after that time” (1958: 212). The assumption that could be drawn from this is
that European beads found a greater place in the African trade after this date.
Placing the Sibudu glass beads in time
One method of placing a glass bead assemblage in time is to compare it to other
assemblages whose dates are known. The calibrated radiocarbon dates place the Iron Age
layers at Sibudu between AD 1020 and 1160. These dates coincide with the K2 period in
the Shashe-Limpopo basin where many thousands of glass beads have been recovered
from archaeological deposits (Fouché 1937; Gardner 1963; Saitowitz 1996; Wood 2005).
Some similarities do exist between the Sibudu and K2-period assemblages: a few tubular
blue-green Sibudu beads (such as SBDU05) are similar to the characteristic K2 ones,
some brownish-red tubular beads are found in K2 assemblages and the yellow and green
beads from both sites are macroscopically similar. The distribution of colours, however,
is very different in that K2 assemblages are made up mainly of blue-green beads, while
brownish-red beads occur in only small numbers (although quantities do increase in the
early thirteenth century) (Wood 2005). In addition, the size and shape of the Sibudu beads,
especially the brownish-red ones, are more uniform than their K2 counterparts. The beads
that solidly demonstrate a lack of connection between the assemblages, however, are
the cobalt blue beads. No cobalt blue beads are found in K2-period assemblages. They
do appear in the bead series that succeed K2 (the Mapungubwe Oblate series and the
Zimbabwe series), but those beads are made of a dark cobalt blue transparent glass that
cannot be mistaken for the glass used to make the translucent-opaque lighter coloured
Sibudu beads. In addition, the glass used to make all Mapungubwe and Zimbabwe series
beads is a plant ash glass (Robertshaw, Wood et al. 2006) so is chemically different
from that used for the Sibudu beads. Cobalt blue beads that are similar visually and
chemically to the Sibudu ones do not appear elsewhere in southern African until about
the fifteenth century as part of the Khami bead series (Wood 2005).
Of other bead assemblages that may be related to the Sibudu beads, such as from
Thulamela (AD 1435–1455 to 1505–1645, Huffman 2007: 253) and Machemma (AD
1410–1440 to 1475–1640, Huffman 2007: 258), only the southern Zambian site of
Ingombe Ilede has beads that are visually similar. They come from burials that date to
the fifteenth century (Huffman pers. comm.). Given the distance between the two sites,
we do not suggest that they were in direct trading contact, but the similarities in the
bead assemblages may indicate they date to around the same time.
The chemistry of Sibudu beads tells us they were made in India, and thus it is likely
they arrived in southern Africa before the end of the seventeenth century when European
beads largely supplanted Indian ones. A mixture of chemistry and comparisons to other
Iron Age bead assemblages in southern Africa make it unlikely they would pre-date the
mid-fifteenth century. Given these parameters, the beads probably date to somewhere
between AD 1450 and 1660 and could have been imported by either non-European or
252
Southern AFRICAN humanities, vol. 21, 2009
European traders since, as was noted earlier, African consumers preferred Indian-made
beads to the ‘new’ varieties.
Where do the Sibudu beads fit in what is now known about bead series in southern
Africa? They do not match the K2 series morphologically or the Mapungubwe Oblate
and Zimbabwe series chemically. They are close to the Khami series chemically but not
morphologically. So it appears that they either post-date the Khami series, and are thus
a new and as yet undefined series, or they are an undefined series that is more or less
contemporaneous with the Khami series. This is a possibility since Portuguese records
tell us that beads were being imported from both northwest (Cambay) and southeast
(Negapatam) India from the beginning of the sixteenth century through to the later part
of the seventeenth century.
The Sibudu bead cache in the context of the Iron Age occupation
To return to the archaeological evidence, it seems worth mentioning that KwaZuluNatal’s Blackburn and Moor Park sequence is not yet well understood and the issue
of whether the Blackburn facies terminates in the Sibudu area at AD 1300 or 1500
depends on whether or not Moor Park is a regional development from it in southern/
interior KwaZulu-Natal (Huffman 2007 and pers. comm. to Wadley). Blackburn might
have continued after AD 1300 only in the north of KwaZulu-Natal (for example, in the
Richards Bay area), until it developed into Nqabeni around AD 1700. If this was the
case, then the Sibudu area would have Moor Park and not Blackburn cultural items
from about AD 1300. Separating the two facies will be difficult based on ceramics alone
because there is overlap in the key features of the ceramics (Huffman 2007). However,
if the termination date for Blackburn is about AD 1500 in the Sibudu area, then there is
not necessarily a contradiction between a fifteenth/sixteenth century glass bead cache
found at Sibudu and the Blackburn cultural remains at the site. The Sibudu ceramics have
not yet been analysed, so it is presently not possible to provide numbers of Blackburn
sherds occurring above and below the hut floor. As a result, it is not yet clear whether
the three radiocarbon dates that calibrate to between AD 1020 and 1160 span the full
Iron Age occupation of the site or whether they date only an early phase of occupation.
Until the glass bead analysis suggested that the beads might post-date the radiocarbon
dates by several centuries, it was assumed that only one Iron Age occupation was
represented at the site. Now it seems possible that the charcoal found within the clay
floor might predate the floor itself and that the floor could be more recent than AD 1160.
If this is the case, then the floor and the bead cache are potentially contemporaneous. If,
however, all the ceramics and the clay floor do represent one Iron Age occupation, the
bead cache must have been buried in the shelter for some unknown purpose after the hut
represented by the clay floor was abandoned. We are consequently uncertain about the
relationship between the bead cache, the Blackburn material culture and the radiocarbon
dates. Resolution of this issue is a project for future research that will involve getting
radiocarbon dates for layer BSV. If the BSV dates prove younger than the date that we
have for the hut floor, this will support the idea that the charcoal embedded in the clay
predates the floor itself and that two Iron Age occupations are represented.
Rarity of glass beads in Iron Age KwaZulu-Natal
As we pointed out earlier, glass beads are rare in Iron Age contexts in the KwaZuluNatal region. Why should this be the case when sites further north have produced
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
253
many thousands of them from as early as the ninth century? From early Arabic
sources, such as al-Masudi, Buzurg ibn Shahriyar, al Biruni and al-Idrisi (Wood
2005: 168–79) it appears that trading ports on the coast did not extend much
south of the Bazaruto area of Mozambique, if at all. Sailing south through the
Mozambique Channel is easy enough since the current flows south year-round,
but the return journey north against the current is difficult so only highly lucrative
trade would have encouraged traders to make the extra effort to journey farther
south. Although KwaZulu-Natal could have provided ivory, a much sought after
commodity in early trade, there was a plentiful supply further north. Ivory trade
from the region began only after Lourenço Marques explored Delagoa Bay in
1545 (Newitt 1995: 152–3). Gold, the one commodity that could have encouraged
traders to undertake the cost and risk to travel further south, was absent in the
KwaZulu-Natal region.
Limited exchange was carried on overland amongst local communities, however.
Evidence for this is sparse, but can be gleaned from reports by early European visitors
to the region, mainly survivors of shipwrecks. As we have noted, the survivors of the
Santo Alberto wreck recorded the use of glass beads by some people they encountered.
In another account by Perestrello, a Portuguese navigator who survived the 1554
wreck of the São Bento, it was recorded that the party encountered a man wearing a
few coriander-seed sized (3–5 mm) red beads,
which we rejoiced to see, it seeming to us that these beads being in his possession proved that
we were near some river frequented by trading vessels, for they are only made in the kingdom of
Cambaya, and are brought by the hands of our people to this coast (Theal 1898, I: 225).
Once again small red beads from Cambay are mentioned. These would have been
brownish-red glass beads—the same sort referred to in the Santo Alberto account and
related to those from the Sibudu cache. However, the paucity of such observations
as well as the absence of glass beads in archaeological sites indicates that they were
very rare indeed in this part of the country. They did not become commonplace until
European trade through Delagoa Bay (Maputo) and eventually Port Natal (Durban) was
well established. Finally, it is always possible that, rather than being a direct product
of trade, the Sibudu cache of glass beads was recovered from a shipwreck on the coast.
If that were the case, however, the beads would have been recovered shortly after the
wreck since they show no sign of water or beach abrasion.
ACKNOWLEDGEMENTS
We thank S. Woodborne of the CSIR for the radiocarbon dates. T.N. Huffman kindly
discussed some of the Iron Age issues relevant to this paper. G. Whitelaw provided
valuable information on archaeological sites and early records. Sibudu research is
financially assisted by the NRF. We thank the School of Geography, Archaeology and
Environmental Studies, University of the Witwatersrand, for ongoing support.
NOTE
An export permit (80/08/06/021/52) was obtained from SAHRA for the non-destructive analysis of 16
glass beads at the Field Museum of Natural History, Chicago, USA. The beads have been returned to
South Africa and are in temporary storage at the University of the Witwatersrand, but they will be housed
in the Natal Museum from 2009.
1
254
Southern AFRICAN humanities, vol. 21, 2009
REFERENCES
Arkell, A.J. 1936. Cambay and the bead trade. Antiquity 10 (39): 292–305.
Axelson, E. 1973. The Portuguese in South-East Africa 1488-1600. Johannesburg: Struik.
Brill, R.H., 1999. Chemical analyses of early glasses. 2 vols. The Corning Museum of Glass, New York.
Chittick, N. 1974. Kilwa: an Islamic trading city on the East African coast. The finds, 2. Nairobi: British
Institute in Eastern Africa.
Cortesão, A. 1944. The Suma Oriental of Tome Pires and the book of Francisco Rodrigues. 2 vols. Ser. Ii,
No. 89. London: Hakluyt society.
Dames, M.L., ed. 1918. The book of Duarte Barbosa, vol. I. London: Hakluyt Society.
Davies, O. 1971. Excavations at Blackburn. South African Archaeological Bulletin 24: 147–64.
Denbow, J. 1986. A new look at the later prehistory of the Kalahari. Journal of African History 27: 3–28.
Dussubieux, L., Kusimba, C.M., Gogte, V., Kusimba, S.B., Gratuze, B. & Oka, R. 2008. The trading of
ancient glass beads: new analytical data from south Asian and east African soda-alumina glass
beads. Archaeometry 50 (5): 797–821.
Dussubieux, L., Robertshaw, P. & Glascock, M. 2009. LA-ICP-MS analysis of African glass beads:
laboratory inter-comparison with an emphasis on the impact of corrosion on data interpretation.
International Journal of Mass Spectrometry 284: 152–61.
Fouché, L. 1937. Mapungubwe, I. Cambridge: Cambridge University Press.
Freeman-Grenville, G.S.P. 1962. The East African coast: selected documents from the first to the early 19th
century. Oxford: Clarendon Press.
Gardner, G.A. 1963. Mapungubwe, II. Pretoria: J.L. van Schaik.
Gratuze, B. 1999. Obsidian characterization by laser ablation ICP-MS and its application to prehistoric
trade in the Mediterranean and the Near East: sources and distribution of obsidian within the
Aegean and Anatolia. Journal of Archaeological Science 26: 869–81.
Huffman, T.N. 2004. The archaeology of the Nguni past. Southern African Humanities 16: 79–111.
Huffman, T.N. 2007. Handbook to the Iron Age: the archaeology of pre-colonial farming societies in
southern Africa. Scottsville: University of KwaZulu-Natal Press.
Karklins, K. 1985. Glass beads: the 19th Century Levin Catalogue and Venetian Bead Book and guide to
description of glass beads. Studies in Archaeology, Architecture and History. Ottawa: Parks
Canada.
Kidd, K.E. & Kidd, M.A. 1970. A classification system for glass beads for the use of field archaeologists.
Canadian Historic Sites: Occasional Papers in Archaeology and History 1: 45–89.
Maggs, T. 1980a. Msuluzi Confluence: a seventh century Early Iron Age site on the Tugela River. Annals
of the Natal Museum 24 (1): 111–45.
Maggs, T. 1980b. Mzonjani and the beginning of the Iron Age in Natal. Annals of the Natal Museum
24 (1): 71–96.
Maggs, T. 1982. Mgoduyanuka: terminal Iron Age settlement in the Natal grasslands. Annals of the Natal
Museum 25 (1): 83–113.
Maggs, T. & Michael, M. 1976. Ntshekane: an Early Iron Age site in the Tugela Basin, Natal. Annals of the
Natal Museum 22 (3): 705–40.
Mazel, A.D. 1986a. Mgede Shelter: a mid- and late Holocene observation in the western Biggarsberg,
Thukela Basin, South Africa. Annals of the Natal Museum 27 (2): 357–87.
Mazel, A.D. 1986b. Mbabane Shelter and eSinhlonhlweni Shelter: the last two thousand years of huntergatherer settlement in the central Thukela Basin, Natal, South Africa. Annals of the Natal
Museum 27 (2): 389–453.
Mazel, A.D. 1993. KwaThwaleyakhe Shelter: the excavation of mid and late Holocene deposits in the
central Thukela Basin, Natal, South Africa. Natal Museum Journal of Humanities 5: 1–36.
Mazel, A.D. 1996. Maqonqo Shelter: the excavation of Holocene deposits in the eastern Biggarsberg,
Thukela Basin, South Africa. Natal Museum Journal of Humanities 8: 1–39.
Miller, D. & Whitelaw, G. 1994. Early Iron Age metal working from the site of KwaGandaganda, Natal,
South Africa. South African Archaeological Bulletin 49: 79–89.
Morrison, H. 1984. The beads. In: N. Chittick, ed., Manda: excavations at an island port on the Kenyan
coast. Memoir 9. Nairobi: British Institute in Eastern Africa, pp. 181–9.
Munsell, C. 1976. Munsell book of color, glossy finish collection. Baltimore: Kollmorgen Corporation.
Newitt, M. 1995. A history of Mozambique. Bloomington & Indianapolis: Indiana University Press.
Pearce, N.J.G., Perkins, W.T., Westgate, J.A., Gorton, M.T., Jackson, S.E., Neal, C.R. & Chenery, S.P.
1997. A compilation of new and published major and trace element data for NIST SRM 610 and
SRM 612 glass reference materials. Geostandards Newsletter 21: 114–15.
Richards, D. 1981. South African shell: a collector’s guide. Cape Town: Struik.
Robertshaw, P., Glascock, M.D., Wood, M. & Popelka, R.S. 2003. Chemical analysis of ancient African
glass beads: a very preliminary report. Journal of African Archaeology 1: 139–46.
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
255
Robertshaw, P., Rasoarifetra, B., Wood, M., Melchiorre, E., Popelka, R.S. & Glascock, M.D. 2006. Chemical
analysis of glass beads from Madagascar. Journal of African Archaeology 4 (1): 91–109.
Robertshaw, P., Wood, M., Popelka-Filcoff, R.S. & Glascock, M.D. 2006. Glass beads of southern Africa
and Indian Ocean trading networks. Paper read at the biennial conference of the Society of
Africanist Archaeologists, Calgary, Canada, June 2006. Available at http://cohesion.rice.edu/
CentersAndInst/SAFA/emplibrary/Robertshaw,P.etalSafa2006.pdf.
Robey, T. 1980. Mpambanyoni: a Late Iron Age site on the Natal south coast. Annals of the Natal Museum
24 (1): 147–64.
Saitowitz, S. 1996. Glass beads as indicators of contact and trade in southern Africa ca. AD 900–AD 1250.
PhD thesis, University of Cape Town.
Schofield, J.F. 1938. A preliminary study of the prehistoric beads of the Northern Transvaal and Natal.
Transactions of the Royal Society of South Africa. 26 (4): 341–71.
Schofield, J.F. 1958. Beads: southern African beads and their relation to the beads of Inyanga. In:
R. Summers, Inyanga: prehistoric settlements in Southern Rhodesia. Cambridge University
Press: Cambridge, pp. 180–229.
Sievers (Scott), C. 2005. Analysis and interpretation of botanical remains from Sibudu Cave, KwaZuluNatal. MSc dissertation, University of the Witwatersrand.
Theal, G.M. 1898. Records of south-eastern Africa. Vols 1 & 2. Cape Town: Government of the Cape
Colony.
Van der Merwe, N.J., Saitowitz, S.J., Thackeray, J.F., Hall, M. & Poggenpoel, C. 1989. Standardized
analyses of glass trade beads from Mgungundlovu and Ondini, nineteenth century Zulu capitals.
South African Archaeological Bulletin 44: 98–104.
Van der Sleen, W.G.N. 1956. Trade-wind beads. Man 56: 27–9.
Van der Sleen, W.G.N. 1958. Ancient glass beads with special reference to the beads of East and Central
Africa and the Indian Ocean. The Journal of the Royal Anthropological Institute of Great Britain
and Ireland 88 (2): 203–16.
Van der Sleen, W.G.N. 1967. A Handbook on Beads. York, Pennsylvania: George Shumway.
Vogel, J.C., Talma, A.S., Fuls, A., Visser, E. & Becker, B. 1993. Pretoria calibration curve for short-lived
samples, 1930–3350 BC. Radiocarbon 35 (1): 73–86.
Wadley, L. & Jacobs, Z. 2004. Sibudu Cave, KwaZulu-Natal: Background to the excavations of Middle
Stone Age and Iron Age occupations. South African Journal of Science 100: 145–51.
Wadley, L. & Jacobs, Z. 2006. Sibudu Cave: background to the excavations, stratigraphy and dating.
Southern African Humanities 18 (1): 1–26.
Ward, V. & Maggs, T. 1988. The slipped disc: a guide to the identification of shell disc-beads. Annals of the
Natal Museum 29 (2): 407–16.
Whitelaw, G. 1994. KwaGandaganda: settlement patterns in the Natal Early Iron Age. Natal Museum
Journal of Humanities 6: 1–64.
Wood, M. 2000. Making connections: relationships between international trade and glass beads from the
Shashe-Limpopo area. South African Archaeological Society Goodwin Series 8: 78–90.
Wood, M. 2005. Glass beads and pre-European trade in the Shashe-Limpopo region. MA dissertation,
University of the Witwatersrand.
drawn
drawn
drawn
drawn
drawn
drawn
1
3
5
34
7
2
SBDU 13
drawn
1
SBDU 11
drawn
27
drawn
drawn
1
1
drawn
1
drawn
2
drawn
drawn
4
1
drawn
1
2
drawn
1
how
made
drawn
quantity
fragments
1
quantity
SBDU 12
bead ID
tube
tube
tube
tube
tube
tube
tube
cylinder
tube
tube
tube
tube
tube
tube
tube
tube
tube
shape
small
minute
lightly
reheated
small
minute
medium
small
small
small
small
minute
heat treated
heat treated
heat treated
heat treated
lightly
reheated
lightly
reheated
heat treated
heat treated
heat treated
small
minute
small
small
minute
medium
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
small
size
range
lightly
reheated
end treatment
short
standard
short
short
short
standard
short
short
short
standard
short
short
standard
short
short
short
standard
length
ratio
APPENDIX 1
Description of loose Sibudu glass beads.
translucent
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
opaque
opaque
opaque/translucent
opaque/translucent
translucent/
opaque
opaque/translucent
?
diaphaneity
2.5BG 6/6
5PB 3/6 to
7.5PB 3/8
5PB 3/6 to
7.5PB 3/8
5PB 3/6 to
7.5PB 3/8
5PB 3/6 to
7.5PB 3/8
shiny to
dull
shiny to
dull
shiny to
dull
shiny to
dull
dull
5PB 2/8
5PB 3/6
blue-green
blue
blue
blue
blue
blue
blue
blue
blue
7.5PB 3/8 to
5PB 3/6
5PB 2/8
blue
black
black
devitrified,
colour gone
devitrified,
colour gone
devitrified,
colour gone
devitrified,
colour gone
colour
group
devitrified,
colour gone
7.5PB 3/8
N 0.5/0.6% R
N 0.5/0.6% R
?
?
?
?
?
Munsell code
shiny
shiny
shiny
shiny
shiny
dull
dull
heavy
patina
heavy
patina
heavy
patina
heavy
patina
crackled
surface
256
Southern AFRICAN humanities, vol. 21, 2009
drawn
drawn
drawn
drawn
drawn
drawn
drawn
drawn
drawn
1
1
1
1
1
1
3
1
3
2
44
4
43
SBDU 08
SBDU 10
SBDU 06
SBDU 05
drawn
drawn
1
drawn
drawn
drawn
drawn
14
1
drawn
1
SBDU 09
drawn
1
how
made
SBDU 07
quantity
fragments
quantity
bead ID
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
heat treated
lightly
reheated
lightly
reheated
lightly
reheated
heat treated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
heat treated
heat treated
lightly
reheated
lightly
reheated
end treatment
small
small
small
small
small
minute
minute
medium
medium
large
minute
minute
small
small
medium
large
small
size
range
long
standard
short
long
short
short
standard
short
short
short
standard
standard
long
short
short
short
short
length
ratio
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
transparent
transparent
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent
diaphaneity
shiny
shiny
shiny to
dull
2.5BG 6/2
5B 5/4 to 10B
4/4
5B 5/4 to 10B
4/4
5B 5/4 to 10B
4/4
5B 5/4 to 10B
4/4
shiny to
dull
shiny
2.5BG 6/6
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
5B 5/4 to 10B
4/4
shiny
shiny
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
blue-green
colour
group
2.5BG 6/2
5B 5/4
shiny to
dull
dull
5B 5/4
shiny
10BG 5/6
2.5B 4/6
very
shiny
shiny
5BG 5/4
10B 4/4
5B 5/4
10BG 5/6
7.5B 6/4
Munsell code
shiny
shiny
shiny
shiny
shiny
surface
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
tube
tube
tube
tube
cylinder
tube
tube
tube
cylinder
tube
tube
tube
tube
cylinder
tube
tube
tube
shape
APPENDIX 1 (continued)
Description of loose Sibudu glass beads.
257
drawn
drawn
drawn
drawn
drawn
drawn
drawn
drawn
183
16
2
320
108
1
8
1198
SBDU 14
drawn
1
drawn
1
SBDU 16
drawn
1
drawn
drawn
1
1
drawn
1
how
made
drawn
quantity
fragments
4
quantity
SBDU 15
bead ID
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
tube
shape
minute
minute
minute
small
small
small
lightly
reheated
lightly
reheated
heat treated/
flattened
lightly
reheated
lightly
reheated
medium
medium
medium
medium
small
small
small
small
small
size
range
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
heat treated/
flattened
heat treated/
flattened
lightly
reheated
lightly
reheated
end treatment
short
long
standard
standard
short
long
standard
short
short
short
short
standard
standard
short
short
length
ratio
APPENDIX 1 (continued)
Description of loose Sibudu glass beads.
opaque
opaque
opaque
opaque
opaque
opaque
opaque
opaque
opaque
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
transparent
diaphaneity
good
good
shiny
good
good
good
good
good
shiny
shiny
shiny
shiny
shiny
dull
shiny
surface
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4
10R 4/4
10R 4/4
10R 4/4
2.5BG 6/2
2.5BG 6/6
2.5BG 6/6
2.5BG 6/2
2.5BG 6/2
Munsell code
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
brownish-red
blue-green
blue-green
blue-green
blue-green
blue-green
colour
group
258
Southern AFRICAN humanities, vol. 21, 2009
drawn
drawn
drawn
drawn
1
1
4
1
SBDU 01
drawn
drawn
1
1
drawn
1
SBDU 02
drawn
1
SBDU 04
drawn
drawn
3
1
drawn
401
how
made
drawn
quantity
fragments
1198
quantity
SBDU 03
bead ID
oblate
cylinder
tube
cylinder
tube
tube
tube
tube
tube
tube
tube
tube
shape
small
lightly
reheated
heat treated
small
small
medium
lightly
reheated
heat treated
small
heat treated
medium
short
short
short
short
short
short
short
minute
small
standard
short
standard
standard
short
length
ratio
small
small
small
small
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
lightly
reheated
size
range
end treatment
APPENDIX 1 (continued)
Description of loose Sibudu glass beads.
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent/
opaque
translucent
opaque
opaque
diaphaneity
dull
shiny
dull
shiny
shiny
dull
shiny
shiny
shiny
shiny
good
good
surface
7.5Y 8.5/10
5Y 8/6
5Y 8/6
7.5Y 7/8
5Y 7/8
10GY 5/4
2.5G 5/6
10GY 5/4
10GY 5/4
10GY 5/4
10R 4/4 to
10R 3/6 to
10R 2/4
10R 4/4 to
10R 3/6 to
10R 2/4
Munsell code
yellow
yellow
yellow
yellow
yellow
green
green
green
green
green
brownish-red
brownish-red
colour
group
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
259
yellow
96
21.2%
1.0%
9.1%
54.2%
0.1%
1.8%
3.5%
6926
297
33
0.07%
2.7%
30
44
0.02%
1961
6
Colour yellow
LiO2
Na2O
MgO
Al2O3
SiO2
P2O5
K2O
CaO
TiO2
V2O5
Cr2O3
MnO
Fe2O3
CoO
NiO
CuO
ZnO
As2O3
60
14.9%
0.9%
7.2%
64.0%
0.1%
3.2%
2.7%
4708
348
34
0.05%
2.1%
21
39
0.05%
406
3
SBDU
02
SBDU
01
Bead
ID
63
19.6%
0.8%
7.6%
59.8%
0.2%
3.1%
3.6%
6004
504
30
0.11%
4.3%
188
44
0.5%
101
170
green
SBDU
03
69
22.2%
0.9%
8.1%
55.3%
0.1%
2.5%
3.5%
7945
582
29
0.06%
6.1%
133
65
0.7%
62
80
green
SBDU
04
SBDU
05
bluegrn
62
19.9%
0.5%
9.3%
60.8%
0.08%
3.6%
2.6%
4785
243
38
0.06%
1.8%
14
28
1.3%
39
7
SBDU
06
bluegrn
72
18.9%
0.9%
8.8%
62.9%
0.1%
2.2%
2.7%
6562
278
47
0.06%
2.4%
25
53
0.8%
586
15
SBDU
07
bluegrn
51
16.5%
0.4%
10.3%
64.9%
0.09%
4.6%
1.6%
3944
326
11
0.06%
1.0%
7.8
20
0.4%
56
17
SBDU
08
bluegrn
53
17.7%
0.7%
4.8%
69.5%
0.08%
1.3%
3.8%
4348
315
41
0.03%
1.5%
160
78
0.5%
37
258
SBDU
09
bluegrn
65
19.1%
0.7%
6.3%
67.3%
0.1%
2.0%
1.8%
4203
311
33
0.05%
1.8%
25
49
0.6%
1157
11
SBDU
10
bluegrn
39
16.0%
0.6%
5.0%
71.0%
0.1%
2.3%
2.5%
3738
374
47
0.08%
1.7%
591
221
0.7%
55
1222
61
19.5%
0.8%
5.7%
66.6%
0.1%
1.8%
3.4%
3515
312
52
0.09%
1.8%
1366
570
0.0%
67
2420
blue
SBDU
11
84
18.4%
1.1%
6.0%
66.0%
0.09%
1.6%
4.6%
4986
287
28
0.04%
2.2%
1624
510
0.0%
44
2388
blue
SBDU
12
68
19.2%
0.9%
7.0%
64.6%
0.2%
2.0%
3.2%
5517
360
71
0.07%
2.5%
2713
1175
0.0%
85
5489
blue
SBDU
13
85
20.2%
1.0%
6.8%
61.5%
0.07%
1.4%
3.4%
5183
265
42
0.09%
3.2%
18
38
0.8%
66
7
br-red
SBDU
14
55
18.4%
0.8%
4.4%
66.4%
0.2%
1.9%
3.0%
3914
358
52
0.04%
2.9%
29
32
0.7%
44
59
br-red
SBDU
15
88
21.4%
0.7%
6.9%
60.7%
0.2%
2.1%
2.1%
4965
363
53
0.07%
3.5%
27
43
0.9%
60
27
br-red
SBDU
16
APPENDIX 2
Results of chemical analysis of Sibudu beads. Concentrations are in weight percent or ppm of oxide (0.1% = 1000 ppm); nm = not measured.
260
Southern AFRICAN humanities, vol. 21, 2009
yellow
62
263
30
360
20
nm
0.5
1.2%
27
0.7
505
51
128
11.4
38
7.1
1.3
Colour yellow
Rb2O
SrO
Y2O3
ZrO2
NbO2
MoO2
InO
SnO2
Sb2O5
Cs2O
BaO
La2O3
Ce2O3
Pr2O3
Nd2O3
Sm2O3
Eu2O3
72
235
21
209
16
nm
0.4
0.6%
7
0.8
345
38
103
9.1
32
5.8
0.9
SBDU
02
SBDU
01
Bead
ID
78
327
19
225
14
nm
0.08
0.09%
16
1.0
434
34
82
7.5
25
4.6
0.9
green
SBDU
03
72
334
20
298
17
nm
0.2
0.09%
23
1.0
428
35
71
7.5
25
4.8
1.0
green
SBDU
04
SBDU
05
bluegrn
142
322
22
783
13
nm
1.1
0.004%
45
1.0
659
25
62
5.9
21
5.4
0.9
SBDU
06
bluegrn
94
238
24
306
18
nm
0.06
0.1%
15
1.8
451
44
96
10.0
34
6.3
1.1
SBDU
07
bluegrn
153
208
25
292
7.6
nm
0.04
0.01%
17
1.1
563
35
78
8.1
27
5.6
0.6
SBDU
08
bluegrn
48
194
17
244
11
nm
0.04
0.001%
13
0.6
290
26
62
5.7
19
3.7
0.7
SBDU
09
bluegrn
51
186
18
200
10
nm
0.1
0.1%
16
0.7
286
28
65
6.4
21
4.0
0.7
SBDU
10
bluegrn
55
176
17
191
10
nm
0.03
0.005%
21
0.6
356
36
72
7.1
24
4.0
0.7
48
241
17
190
11
nm
0.04
0.01%
2.5
0.6
355
32
67
6.5
22
3.9
0.7
blue
SBDU
11
47
200
21
234
13
nm
0.03
0.0005%
1.4
0.9
277
36
78
7.7
26
4.8
0.9
blue
SBDU
12
68
255
25
246
16
nm
0.03
0.02%
3.2
0.9
554
49
105
10.1
34
6.3
1.2
blue
SBDU
13
42
267
23
345
17
1.5
0.04
0.007%
21
0.4
353
44
89
9.6
31
6.0
0.8
br-red
SBDU
14
46
201
19
444
12
6.0
0.06
0.005%
24
0.6
255
30
68
6.4
21
3.8
0.6
br-red
SBDU
15
80
169
25
258
16
6.6
0.05
0.005%
30
0.8
354
40
102
8.8
29
5.4
0.9
br-red
SBDU
16
APPENDIX 2 (continued)
Results of chemical analysis of Sibudu beads. Concentrations are in weight percent or ppm of oxide (0.1% = 1000 ppm); nm = not measured.
WOOD ET AL.: a GLASS BEAD CACHE FROM sIBUDU CAVE
261