By the 1930s, the electronics industry had become dependent on quartz crystals. The only source of suitable crystals was Brazil; however, World War II disrupted the supplies from Brazil, so nations attempted to synthesize quartz on a commercial scale. German mineralogist Richard Nacken (1884–1971) achieved some success during the 1930s and 1940s.  After the war, many laboratories attempted to grow large quartz crystals. In the United States, the U. S. Army Signal Corps contracted with Bell Laboratories and with the Brush Development Company of Cleveland, Ohio to synthesize crystals following Nacken's lead.  (Prior to World War II, Brush Development produced piezoelectric crystals for record players. ) By 1948, Brush Development had grown crystals that were 1. 5 inches (3. 8 cm) in diameter, the largest to date.  By the 1950s, hydrothermal synthesis techniques were producing synthetic quartz crystals on an industrial scale, and today virtually all the quartz crystal used in the modern electronics industry is synthetic.