The thermal expansion of zircon is quite low, with an average (bulk) coefficient of thermal
expansion (β) of approximately 4.5 × 10-6/°C. As would be expected from the structure, the
thermal expansion of zircon is anisotropic, with expansion along [001] greater than along
(β = 3.2 × 10-6/°C and β [001] = 5.4 × 10-6/°C, Bayer 1972). Bayer (1972) examined the
thermal behaviors of several synthetic ATO4 compounds with zircon and scheelite structures and
found that the thermal expansion of compounds with the zircon structure is generally less than
that of scheelite-type compounds, and that thermal expansion tends to increase with decreasing
valence of dodecahedral-site cations.