Practice 1 thin section and hand specimen , corundum - sillimanite - orthoclase gneiss resembling kash system .
薄片和手标本，刚玉－夕线石－正长石片麻岩，似kash系统。
Developing straegy research industry planning ; project evaluation and project consulting & design in non-metallic minerals such as graphite , kaolin , talc , attapulgite , bentonite , sillimanite gypsum etc.
