A Stereographic Construction for Determining the Optic Axes of a Biaxial Crystal Directly from a Few Extinction Measurements

N. Joel
Centro de Investigaciones de Cristalografía, Instituto de Física y Matemáticas, Universidad de Chile, Casilla 2777, Santiago, Chile

Summary: It is possible to determine the directions of the optic axes of a biaxial crystal mounted on a spindle stage—and hence the angle 2V and the directions of α, β, γ—from only four measured extinction positions. The method is a generalization of the one proposed by Tocher (1962); but in the present procedure it is not necessary to determine first the optic axial plane.

Mineralogical Magazine; March 1964 v. 33; no. 264; p. 769-779; DOI: 10.1180/minmag.1964.033.264.05
© 1964, The Mineralogical Society
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