Abrammuo: The Akan Goldweights, Proverbial Wisdom, and the Art of Measuring Value in Pre-Colonial Ghana

Long before European ships appeared off the Gold Coast, the Akan peoples had developed one of the most sophisticated systems of commercial measurement in pre-colonial Africa. The abrammuo (singular: mrammuo) — small brass weights used to measure gold dust (sika futuro) in trade — emerged around 1400 AD among the forest-dwelling Akan, coinciding with the expansion of gold mining in the Birim, Offin, and Pra river valleys. An estimated four million goldweights were cast between 1400 and 1900 by the Ashanti and Baule ethnic groups alone, making them perhaps the most prolific tradition of small-scale metal sculpture in African history.

The earliest weights were geometric: pyramids, cubes, cylinders, discs, and stepped forms, cast using the lost-wax (cire perdue) method. Goldsmiths (adwumfo) carved a beeswax model, encased it in clay, heated it to melt the wax out, and poured molten brass (an alloy of copper and zinc, often recycled from European trade goods — manillas, basins, and later cartridge casings) into the mould. The precision was remarkable: the Akan system had over sixty standardised values, ranging from weights as small as 0.04 grams to heavy trade weights exceeding 2,000 grams. A complete set of weights was a prerequisite for any man entering trade; newly married men received a starter set as a wedding gift, signalling their readiness for commercial life.

The weight system tracked two parallel standards: the local Akan system based on the taku seed (Abrus precatorius, averaging 0.13g) and, after Portuguese contact in 1471, an adapted system that accommodated European ounce and troy standards. The goldsmith had to judge the exact amount of molten metal required; if the casting was too heavy, holes were drilled to remove brass, and if too light, small nuggets were soldered on — evidence of this fine-tuning survives on thousands of extant weights.