Porphyritic - Wikipedia Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts
What is a Porphyritic Texture and How Is It Formed? The porphyritic texture is an igneous rock texture characterized by well-formed, larger crystals in a finer-grained matrix The consistently larger crystals are known as phenocrysts, while the finer-grained matrix is known as groundmass
Porphyritic – Geology is the Way The porphyritic texture is a type of texture occurring in volcanic and intrusive igneous rocks defined by the presence of larger crystals, called phenocrysts, surrounded by a matrix of considerably smaller crystals or igneous glass, called groundmass
The Textures of Igneous Rocks – Geology In Porphyritic texture also occurs when magma crystallizes below a volcano but is erupted before completing crystallization thus forcing the remaining lava to crystallize more rapidly with much smaller crystals Examples of porphyritic igneous rocks include andesite and porphyry
Porphyry | geological feature | Britannica They commonly have a porphyritic texture, i e , larger crystals within a finer-grained groundmass, indicating two periods of crystallization (A porphyry is an igneous rock containing conspicuous crystals, called phenocrysts, surrounded by a matrix of finer-grained minerals or glass or both )
Porphyry (geology) - Wikipedia The adjective porphyritic now refers to a certain texture of igneous rock regardless of its chemical and mineralogical composition or its color Its chief characteristic is a large difference in size between the tiny matrix crystals and the much larger phenocrysts