We analysed a faience fragment from Bristol Museum and Art Gallery, to determine whether it belonged to the Town Mosaic, excavated at Knossos. Three Town Mosaic fragments from the Ashmolean Museum, Oxford were also examined. The objects were analysed using non-destructive variable-pressure scanning electron microscopy with energy-dispersive X-ray spectrometry. The Bristol object's composition and microstructures are similar to those of the Town Mosaic samples. Our results are also comparable to those from polished samples of Minoan faience (Tite et al. 2009), showing that VP SEM–EDX gives reliable results without invasive sampling. Silicaceous, copper-rich microspheres were identified for the first time in two of the Ashmolean objects.