Sahelian
The Ghana Empire, Mali Empire, and Songhay Empire were major exporters of gold, iron, tin, slaves, spears, javelin, arrows, bows, whips of hippo hide. They imported salt, horses, wheat, raisins, cowries, dates, copper, henna, olives, tanned hides, silk, cloth, brocade, Venetian pearls, mirrors, and tobacco.
Some of the currencies used in the Sahel are as follows: 1. Paper debt or IOU's were used for long distance trade. 2. Gold coins were also in use. 3. The mitkal(gold dust) currency was in use. It was gold dust that weighed 4.6 grams equivalent to 500 or 3,000 cowries. 4. Square cloth, four spans on each side, called chigguiya was used around the Senegal River.
In Kanem cloth was the major currency. A cloth currency called dandi was in widespread use.
Read more about this topic: Science And Technology In Africa, Commerce