The Thermal Expansion of the Sodalite Group of Minerals

D. Taylor
Department of Geology, University of Manchester1
1Present address: Doulton Research Limited, Hanworth Lane, Chertsey, Surrey.

Summary: Thermal expansion data up to 920° C by powder X-ray diffraction methods are presented for four noseans, five haüynes, and one sodalite. The rate of thermal expansion is at first high and increases with temperature; this is interpreted as due to the untwisting of the partially collapsed framework. Above a certain temperature (which depends on the mineral and its composition) the rate of thermal expansion is much lower and is linear with temperature; this corresponds to the rate of thermal expansion of the more fully expanded framework. Sodalite does not show this second stage below 920° C. The thermal expansion behaviour of other framework silicates is interpreted in analogy to that of the sodalite group.

Mineralogical Magazine; June 1968 v. 36; no. 282; p. 761-769; DOI: 10.1180/minmag.1968.036.282.02
© 1968, The Mineralogical Society
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