Extinction Curves and Equivibration Curves Obtained with a Variable-Axis Spindle-Stage

H. Villarroel and N. Joel1
Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Casilla 2777, Santiago, Chile
1Present address of N. J.: Dept. of Natural Sciences, UNESCO, Place Fontenoy, Paris 7э, France.

Summary: A modification of the one-axis spindle-stage for the study of the optical indicatrix of crystal grains on the polarizing microscope is described. It allows the crystal to be rotated around axes within a range of about 40° without having to remount it. Some advantages of this variable-axis spindle-stage for obtaining extinction curves and equivibration curves (n0 curves) are illustrated.

Mineralogical Magazine; March 1967 v. 36; no. 277; p. 127-130; DOI: 10.1180/minmag.1967.036.277.19
© 1967, The Mineralogical Society
Mineralogical Society (www.minersoc.org)