A substance which forms the material of certain kinds of bead used in West Africa. Chiefly in "aggry bead": a type of variegated glass bead found especially in Ghana.
There is no consensus on the designation, composition, origin, and colour of aggry in its early history. The earlier accounts describe it variously as stone, coral, marble, amber, or porcelain, and later ones add glass, either natural or artificial; the latter seems to be the composition favoured by historians. Any old and valuable glass bead found in West Africa, whatever its source or colour, now tends to be called an aggry bead.
Late 17th century. Origin unknown. Probably from a West African language.