The valuable substance in the "Dune" universe, as referenced in the New York Times crossword, is called "spice" , also known as spice melange. It is the most precious commodity in the Dune universe, known for extending life, enhancing mental abilities, and enabling safe interstellar travel. The spice is found exclusively on the desert planet Arrakis and is central to the economy, culture, and power struggles within the Dune series.
