The thermal behaviour of sacrofanite
The thermal behaviour of sacrofanite, the ABCABACACABACBACBACABABACABC 28-layer member of the cancrinite sodalite supergroup has been investigated in situ using laboratory focussing-beam X-ray powder diffraction data. Thermal expansion has been analysed from 303 to 873 K. A moderate anisotropy has been observed at T > 473 K, the c-parameter being softer than the a-parameter. At ca. 800 K the unit cell starts to compress owing to (partial) dehydration.