Protoenstatite: a crystal-structure refinement at 1100°C

Abstract

Techniques allowing single-crystal investigations on the precession camera up to the melting point of platinum have been developed. The crystal structure of protoenstatite has been refined from three-dimensional intensity data obtained at 1100°C using a crystal of enstatite from the Norton County, Kansas meteorite. The space group is P2₁ cn, a subgroup of the previously proposed Pbcn, and the cell dimensions are: a = 9.304(4), b = 8.902(4), c = 5.351(3) Å. The structure shows strong stacking disorder along the a axis, probably resulting from incomplete inversion from orthoenstatite.