In some African languages, the word for “iron” also means “a thing of value” or, more specifically, “money.” All over the continent, blacksmiths made metal currency for many hundreds of years before colonial authorities imposed the institution of minted coinage from the late nineteenth century onward. The currency might come simply in the form of ingots or crosses of iron, but also in a variety of forms modeled on functional objects, like hand tools or weapons. Among the most spectacular examples are the enormous blades used by the Topoke, Lokele, and neighboring peoples of the Democratic Republic of Congo. Representing wealth and authority, they look like spearheads, but their makers did not use them as weapons. They served in important exchanges, including land deals, payments of ritual fines, purchases of canoes, and marriage compensations offered to the family of the bride. The Belgians banned their usage in the early 1920s, as all Congolese people were obliged to earn colonial francs to pay taxes.

In general, the blades range from 140 cm to 200 cm, taller than a person. These examples fall in the 141 - 166 cm range. The blades are known by several names—including liganda, dihunga, and doa—depending on their size and their origin. The greatest number of blades come from the Topoke and Lokele peoples, yet neighboring Hanga, Olombo, and Turumbu smiths welded this type of currency too, each having their own terminology. Most old specimens show parallel incisions along the left edge of each face, creating a subtle asymmetry. The blades end in a hollow, cylindrical extension that either held a wooden pole or was stuck directly into the ground. One of the blades here appears to have been painted, and an example with red and white pigments is known from the literature. The meaning of the colors is not known, however.