They really help in the process of Africa's state building, creating commercial networks between parts of the continent, and introducing literacy ( especially on northern part of Africa)
They also controlled the sea route between Asia and Africa and managed to maintain the relationship between Africa and the middle east
Fertilizer to balance the high alkalinity of the soil.
Texture
-Hardness
-Luster or shine
-Color/streak
So as to find the pattern repeat. Patterns are why we do what we do, the way we do them & how we do them, while observing who we'd most like to be or look like or have the possessions of.
