Porphyry (geology) - Wikipedia
Porphyry (/ ˈpɔːrfəri / POR-fə-ree) is any of various granites or igneous rocks with coarse-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate -rich, generally aphanitic matrix or groundmass.
What Is Porphyry? How Does It Form, and In Which Rocks?
2022年9月2日 · Porphyry (pronounced as POR-fə-ree) describes any intrusive or extrusive igneous texture rock with large-grained crystals embedded in a finer-grain matrix. The finer-grained groundmass or matrix can be aphanitic or phaneritic. However, the larger crystals must be easily noticed and distinguishable.
Porphyry - Igneous Rocks - Sandatlas
Porphyry is an igneous rock characterized by porphyritic texture. Porphyritic texture is a very common texture in igneous rocks in which larger crystals (phenocrysts) are embedded in a fine-grained groundmass.
Porphyry In Geology and Rock Examples? | Earth Know
2024年5月8日 · A porphyry (plural porphyries) is an igneous rock with large, well-formed mineral grains set in a finer-grained matrix. Such rocks have two distinctive crystal sizes: large and small. The larger mineral grains are called phenocrysts.
Porphyry | geological feature | Britannica
(A porphyry is an igneous rock containing conspicuous crystals, called phenocrysts, surrounded by a matrix of finer-grained minerals or glass or both.) In most rocks, both alkali and plagioclase feldspars occur as irregularly shaped grains with only a few or no crystal faces.
Porphyry (geology) - New World Encyclopedia
Porphyry is a variety of igneous rock consisting of large-grained crystals, such as feldspar or quartz, dispersed in a fine-grained feldspathic matrix or groundmass. The larger crystals are called phenocrysts .
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?
2022年9月2日 · 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.
What Is Porphyritic Texture in Rocks and How Does It Form
2024年5月8日 · Originally, porphyry referred to the purple or red porphyritic dacitic rock mined in Egypt. This rock, called red, purple, or Roman Imperial porphyry, was highly valued during antiquity as a dimensional stone and was used to make sculptures among the …
Porphyry: Mineral information, data and localities. - mindat.org
An igneous rock of any composition that contains conspicuous phenocrysts in a fine-grained groundmass; a porphyritic igneous rock. The term (from the Ancient Greek word πορφύρα (porphyra) for the colour purple and a purple dye) was first applied to a purple-red rock quarried in Egypt and characterized by phenocryst s of alkali feldspar.