Dislocations and their spatial configuration in amethyst crystals

Etch patterns produced on habit rhombohedral faces and rhombohedral cleavages of amethyst crystals are described and illustrated. Fidelity of etchants used is assessed. Also described are paired pits produced on match cleavages etched with the same or different etchants. By prolonged etching experiments it is established that the dislocations penetrate into the body of the crystal. Spatial distribution of dislocation in the body of the crystal is worked out. Uniformly spaced etch pits in an array observed on match cleavages (etched with different etchants) are attributed to low-angle tilt boundaries.