A model of the heliocentric dust cloud is constructed which allows for the variation of temperature with particle sixe and optical properties, and the thermal emission is computed. The results show that a stony dust material produces two emission peaks at near-infrared wavelengths. Comparison with recent observations at wavelength 2.2 indicates that there are two dust materials present near the Sun. The positions and radiance of the observed peaks allow an estimation of the properties of these materials and the size distribution and space density of the dust particles. The thermal emission predicted by the model is computed at longer wavelengths for comparison with future observations, and the variation with wavelength is found to reflect the reststrahlen band structure of the dust materials.