The effects of temperature and bismuth impurities on preferred orientations of copper and silver on amorphous silica are studied for the temperature range 74 to 98% of the melting temperature of the metal phases. It is shown that, at low temperatures, two preferred orientations exist for both pure metals, which have either the (111) or the (100) plane of the metal phase parallel to the silica substrate. Increasing the temperature results in a gradual elimination of the (100) preferred orientation, such that at 98% of the melting temperature, only the (111) orientation remains present. On the other hand, the addition of bismuth is observed to have a stabilizing effect on the (100) orientation, such that this orientation occurs even at the highest annealing temperatures. These results will be discussed in terms of the interfacial energy curves for metal/amorphous silica interfaces.