Chile saltpeter is the common name of:

Sodium Nitrate (NaNO₃) is also known as Chile saltpeter or Peru saltpeter (due to the large deposits found in the Atacama desert in these countries) to distinguish it from ordinary saltpeter, potassium nitrate. Also known as soda niter, it is used in the production of fertilizers, pyrotechnics and smoke bombs, glass and pottery enamels, food preservatives, and solid rocket propellant.