Phenocryst - Wikipedia
网页A phenocryst is an early forming, relatively large and usually conspicuous crystal distinctly larger than the grains of the rock groundmass of an igneous rock. Such rocks that have a distinct difference in the size of the crystals are called porphyries, and the adjective porphyritic is used to describe them.
Phenocryst & Porphyritic Textures - Science Trends
网页A phenocryst is a large crystal that visually stands out compared to the rest of the minerals. Phenocrysts are found in porphyritic textures where large grains are visible in volcanic extrusive rocks.
Phenocryst | crystal | Britannica
网页In igneous rock: Fabric. …as separate entities, known as phenocrysts, set in a groundmass or matrix of much finer-grained crystalline material or glass. Quite commonly in many volcanic rocks, phenocrysts are aggregated.
Porphyritic - Wikipedia
网页The term comes from the Ancient Greek πορφύρα (porphyra), meaning " purple ". Purple was the color of royalty, and the "imperial porphyry " was a deep purple igneous rock with large crystals of plagioclase, prized for monuments and building projects due to its hardness.
Common Igneous Textural Terms and photomicrographs
网页Graphic texture visible only under the microscope. Granophyric. A texture of certain porphyritic rocks in which the groundmass minerals (usually quartz and alkali feldspar) penetrate each other as feathery irregular intergrowths. Resembles micrographic texture, but is more irregula.
Phenocryst - an overview | ScienceDirect Topics
网页Phenocrysts are relatively large crystals that are present in magma and can be easily recognized in lavas. In plutons, they may be mistaken for crystals that formed after the magma was emplaced. The Encyclopedia of Volcanoes (Second Edition), 2015. About this page. Chapters and Articles.
4.3 Classification of Igneous Rocks – Principles of Earth Science
网页Igneous rocks are classified according to the relative abundances of minerals they contain. A given rock is represented by a vertical line in the diagram. In the mafic field, the arrows represent a rock containing 48% pyroxene and 52% plagioclase feldspar.
Phenocryst - an overview | ScienceDirect Topics
网页A 'phenocryst' refers to unusually large or distinctive crystals found in magmatic rocks, distinguishing them from the smaller groundmass crystals. These crystals are believed to form during slow cooling processes at depth in the Earth's crust.
Phenocryst - SpringerLink
网页A phenocryst is a large crystal in an igneous rock. It is a cognate crystal, almost invariably early formed, and is genetically distinct from a xenocryst (Iddings, 1889). Its derivation is from Greek phaneros, conspicuous, and kristallos, a crystal.
Geochemical insights from clinopyroxene phenocrysts into the …
网页2018年9月1日 · The phenocryst assemblages are mainly composed of euhedral to subhedral clinopyroxene, plagioclase, K-feldspar and/or biotite (Fig. 2). Accessory minerals such as Fe-Ti oxides and zircon are commonly found as inclusions in plagioclase and clinopyroxene phenocrysts.
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