UNESCO Ancient Civilizations of Africa (Editor G. Mokhtar)

Ancient Civilizations of Africa
feature of Ghanaian archaeology appear in part to be fashioned from a single
rock-type 20 which was traded over a wide area. All over sub-Saharan Africa
grooves normally 10-12 centimetres wide and up to 50 centimetres long
mark the spots where suitable flaked stone roughouts were ground to make
axes, adzes and chisels. It is probable that the process of quarrying, albeit
on a small scale, grinding, polishing and trading of either the roughouts or
the finished products went on throughout the period in diminishing intensity
as iron replaced stone. In some areas ground-stone tools were,
however, still in use in the second millennium of our era. Surprisingly few
groundstone tools have been found in East and southern Africa though
they are extremely common in West Africa.
Grey vesicular lava, which like latérite is easier to shape on first exposure
to the air, was quarried for stone bowls in Kenya and possibly Tanzania
during the first millennium before our era. Their use is unknown: many
of those found were associated with burials. They are too soft for grinding
anything but soft vegetable foods. Similar bowls have been found in
Namibia, but elsewhere they are rare.
Another relatively unexplored activity which certainly took place was the
search for suitable semi-precious stones to make into beads: cornelian and
various forms of chalcedony such as agates and jaspers, as well as
crystalline quartzes or rock crystal, were the most common. Beads of these
materials are found all over sub-Saharan Africa - often in graves such as
those at the Njoro river cave site in Kenya, dated to the tenth century
before our era and also on habitation sites. At Lantana in Niger 2 ' a mine for
red stone (jasper) which is still traded to Nigeria for bead-making is believed
to be very old, but it is impossible to date its origin. Rarely abundant,
stone beads nevertheless indicate a deliberate search for well-known rock
types. Such beads were, of course, made as long ago as stone age times and
were to continue being made right throughout the iron age until gradually
replaced by the cheaper, more easily made and eventually more accessible
glass trade-beads.
Trade 22
Some form of exchange has gone on between communities probably
from relatively early stone age times. The exchange of bright or useful
stones and honey for meat and occasionally even womenfolk probably
marked the gatherings of foraging peoples, if models based on the
study of modern hunters and food-gatherers are any guide. Such exchanges,
which were of both a ritual and economic significance, would have become
regular as societies entered into an agricultural existence, though even in late
20. M. Posnansky, 1969-70, p. 20.
21. G. de Beauchêne, 1970, p. 63.
22. See Chapter 21 and M. Posnansky, 1971.
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