Explanation
porphyry is a kind of neutral, acidic or alkaline igneous rock with porphyritic texture (it can be intrusive rocks or extrusive rock). They are usually scattered and distributed between fine crystalline minerals called "matrices". It is the general name of igneous rock characterized by porphyritic texture and the name of rock based on its structural characteristics. It is relatively solid and can be used as building materials. The phenocryst is generally composed of alkaline feldspar or quartze, and the matrix is fine-grained or cryptocrystalline (vitreous).
Classification
Natural materials and products -> Mineral materials