MICROSTRUCTURAL DESCRIPTION OF FIBROUS GYPSUM VEINS FROM SOUTH OF KORGALZHYN DISTRICT, AKMOLA REGION

Abstract

Samples from Korgalzhyn district are probably fibrous gypsum veins that recrystallised completely into selenite. As a result of recrystallization, the gypsum veins that were originally vertical fibers became into horizontally interlocked crystal plates. What looked like median planes appear actually to be vein-parallel fractures developed parallel to (010), the most easy fracture direction in gypsum. The plane (010) lies parallel to the vein walls. The preferred crystallographic orientation of gypsum crystal is that <b> axes is perpendicular to the vein, and <b> plane is parallel to vein walls.