Modified Technique for staining feldspar in grain mounts (Note)

Abstract

Abstract A modified technique for stain differentiation of potassium feldspar and plagioclase in sand grain mounts is described. Because the red amaranth plagioclase stain is rather soluble in water, grain mounts should be dried as rapidly as possible after the final rinse. Mounting the grains on solvent-resistant plastic permits the use of an acetone wash which rapidly removes water from the surface of the slide. Because the amaranth stain is almost insoluble in acetone, fading of the red colouration by sol ution is effectively halted. Mounting the grains in linear zones allows rapid counting without the use of a grid.