A new model for interstellar dust

Some physical, chemical and optical properties of mixed oxide grain material are discussed and the formation of such dust is examined. Surface chemistry on these grains may be responsible for the selective depletion of elements and for the formation of molecules such as H₂CO in diffuse clouds. Spectra of mixed oxide grains yield features at 9.6 and 18 m together with a broad band at 4.6 m^–1.Invited contribution to the Proceedings of a Workshop onThermodynamics and Kinetics of Dust Formation in the Space Medium held at the Lunar and Planetary Institute, Houston, 6–8 September, 1978.