Rapid identification of steatite–enstatite polymorphs at various temperatures

The mechanical properties of steatite ceramics after high-temperature processing depend on inversion of high-temperature Mg_2Si_2O_6 protoenstatite polymorph to low clino- or ortho-enstatite, which are characterized by Raman spectroscopy. The Raman spectrum of a pure Mg_2Si_2O_6 protoenstatite is sufficiently distinct from those of low clino- and ortho-enstatite to allow rapid identification in a bulk sample both at ambient and high temperatures. With its high-lateral resolution (about 2 μm), speed, and ease of application on rough materials, Raman spectroscopy can be used to map transformation sequences of enstatite in quenched materials or at high temperature during the fabrication of the steatite-type ceramics, and their relationship with microstructural defects such as voids and cracks.