Enstatite thermal expansion

Enstatite. Magnesium metasilicate MgSi03 m.p. 1550°C. Enstatite (orthorhombic) is stable up to about 1050°C when it inverts to proto-enstatite (orthorhombic) which is the stable high temperature form. Clino-enstatite (monoclinic) is formed as a metastable phase when proto-enstatite is cooled rapidly the transition temperature is 865°C. Thermal expansion (300-700°C) enstatite 12 x 10- proto-enstatite 10 x 10- clino-enstatite 13.5 x 10-, Proto-and/or clino-enstatite are major constituents of steatite ceramics clino-enstatite is found in magnesite refractories that have been attacked by siliceous slags. 

With the use of the thermal expansion data of Skinner (1966) for diopside, enstatite, spinel, pyrope and forsterite, the volume change at lOOO C is -7.61 cm. Thus, fortunately, the differential thermal expansion may be ignored. 

---