A series of mixed silver halide crystals of composition AgClxBr1-x (0≤x≤1) have been extruded into 0.9 mm diameter fibers of several meters length. The intrinsic absorption edges that define the infrared spectral window of these crystalline solids, namely band-to-band transitions in the U.V.-visible, and multiphonon processes in the infrared, have been measured as a function of composition. Optical losses have been measured at a wavelength of 10.6 μm in these fibers. The average loss at this wavelength totals about 0.15 dB per meter, of which about 0.08 is attributable to bulk scatter, 0.04 to "hot spots" (which we relate to macroscopic defects), and 0.03 to extrinsic absorption. The far field power distribution of the fiber output, and the total light scatter were measured and were found to vary with fiber length. These results are consistent with a model that postulates the presence of large scale scatterers in the fiber which cause diffusion of power between guided rays until steady state is reached.