As part of a broad program on minerals research by the U.S. Bureau of Mines, infrared spectroscopy is being used at its Morgantown, W. Va., laboratories for the study of various minerals of current interest to both Government and industry. One of these is the mineral dawsonite, a basic carbonate of sodium and aluminum, NaAl(CO3)(OH)2. A recent report (Smith and Milton, 1966) describes relatively abundant deposits of this mineral as a rock-forming constituent of oil shale in the Piceance Creek Basin of northwestern Colorado. This occurrence has created interest in dawsonite as a potential ore of aluminum. In addition, alkalized alumina (synthetic dawsonite) prepared by the reaction of aluminum sulfate and sodium carbonate, is being tested by the Bureau of Mines as an absorbent for sulfur dioxide in flue gas. This note presents the infrared spectrum of pure natural dawsonite, compares it qualitatively with synthetic dawsonite, and demonstrates that infrared spectroscopy to 200 cm-1 is a reliable method for the identification and possible quantitative analysis of this mineral.