These beads are of the kind known as 'trade', 'aggry' or, sometimes, 'slave' beads. They are usually associated with West Africa but were originally created in Europe. The history of trade beads dates to the 15th century when Portuguese trading ships arrived on the coast of West Africa to exploit its many resources, including gold, slaves, ivory and palm oil. At that time, beads were a major part of the currency exchanged for people and products. Over the following four centuries millions of beads were traded to Africa and by the 19th century European bead makers were producing a wide variety of designs specifically for the African trade.

These twenty-four beads are made of carnelian. The vibrant colour is achieved by heating and shaping the stone which probably came from South America but was formed into beads at the German bead-making centre of Idar-Oberstein. The popularity of the elegant, smooth geometric forms of Idar-Oberstein beads undermined the Indian carnelian industry, which had been supplying stone beads to Africa for centuries.