Two centuries ago the diet of technology (the diversity of materials utilized) consisted largely of natural
materials and a few metals. A century later, the diversity in the diet had expanded to perhaps a dozen
materials in common use. In contrast, today’s technology employs nearly every material in the periodic
table, a behavior illustrated in this paper by the material evolution of electronics, medicaltechnology, and
the jet engine. Geological deposits in a given country or region tend to have only minimal to moderate
elemental diversity, however. As a result, an extensive and diverse metal trade is required if modern
technology is to be sustained. Some recent industry responses to elemental scarcity and implications for
corporate and governmental policy are discussed