From the 15th through the 19th centuries, gold brought great prosperity and power through trade to the Akan and Akan-related people of southern Ghana and Côte d’Ivoire. To regulate trade in gold, Akan merchants and rulers developed brass weights called abrammuo (singular mrammuo) that established standard units of measurement. The earliest and most common gold weights were cast in abstract, geometric forms. This weight is in the shape of a pyramid, symbolic of wealth, history, and longevity; with its stepped design it was also probably easy to grasp with the hand.