Copper has been mined in the land area between central Chile and southern Peru since Colonial times. Yet it was not until the 20th century that copper reached the importance of other mining exports such as saltpeter or silver. Before the first world war, saltpeter, collected in Chile from abundant deposits of caliche in the Atacama Desert, was the main source of nitrates in the world. After the World War I, because of the production of artificial nitrates, synthesized first in Germany by the combination of the Haber process and the Ostwald process, the world market for saltpeter, which was Chile’s main export, collapsed. In turn, Chile’s economy became heavily dependent on the copper industry. It was from that period that copper became known as “Chile’s salary”.