Explanation
A extrusive rock with composition equivalent to nepheline syenite. It is named after a unique sound when striking the plate joints of rock. The main mineral components are alkaline feldspar, feldspathoid, alkaline pyroxene and alkaline amphibole. Most are porphyritic texture, and the matrix is often aphanitic. Rock is usually gray white or dark gray. According to the type and content of feldspathoid, it can be divided into nepheline, leucite, etc. Often occurring as small rock flows or rock clocks, distributed in alkaline rock areas. The minerals related to it are gold and copper. It can be used as building decoration materials.
Classification
Natural materials and products -> Mineral materials