Explanation

A compacted and consolidated acidic volcanic shoulder rock. The content of volcanic debris is over 50%, with a particle size of<2mm. It is cemented by finer volcanic debris (volcanic dust) and the chemical decomposition products of volcanic ash water, forming a typical tuff structure. Poor sorting and unclear layered structure. Volcanic debris includes rock debris, crystal debris, and glass debris, but mainly consists of glass debris and crystal debris, with rock debris generally not exceeding 20%. The crystal chips are mainly quartze and alkaline feldspar. It is light green, purple red, and dense. It is closely related to the metallogenesis of zeolite, montmorillonite and other non-metallic minerals. Dense and hard materials can be used as building decoration materials.

Classification