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Porphyrian trees by three authors: Purchotius (1730), Boethius (6th century), and Ramon Llull (ca. 1305). In philosophy (particularly the theory of categories), the Porphyrian tree or Tree of Porphyry is a classic device for illustrating a "scale of being" (Latin: scala praedicamentalis), attributed to the 3rd-century CE Greek neoplatonist philosopher and logician Porphyry, and revived through ...
"Imperial Porphyry" from the Red Sea Mountains of Egypt A waterworn cobble of porphyry Rhyolite porphyry from Colorado; scale bar in lower left is 1 cm (0.39 in). Porphyry (/ ˈ p ɔːr f ə r i / 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.
It was composed by Porphyry in Sicily during the years 268–270, and sent to Chrysaorium, according to all the ancient commentators Ammonius, Elias, and David. The work includes the highly influential hierarchical classification of genera and species from substance in general down to individuals, known as the Tree of Porphyry , and an ...
Porphyry (geology), an igneous rock with large crystals in a fine-grained matrix, often purple, and prestigious Roman sculpture material; Shoksha porphyry, quartzite of purple color resembling true porphyry mined near the village of Shoksha, Karelia, Russia; Porphyritic, the general igneous texture of a rock with two distinct crystal ...
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
[1] [2] Most porphyritic rocks have bimodal size ranges, meaning the rock is composed of two distinct sizes of crystal. [ 3 ] In extrusive rocks, the phenocrysts are surrounded by a fine-grained (aphanitic) matrix or groundmass of volcanic glass or non-visible crystals, commonly seen in porphyritic basalt .
The post If You See Paint on Trees, This Is What It Means appeared first on Reader's Digest. ... “That can lead to confusion when trying to generalize the meaning of different symbols and colors
Cartoon cross-section showing manto ore deposits (USGS) [1] A polymetallic replacement deposit, also known as carbonate replacement deposit or high-temperature carbonate-hosted Ag-Pb-Zn deposit, [2] is an orebody of metallic minerals formed by the replacement of sedimentary, usually carbonate rock, by metal-bearing solutions in the vicinity of igneous intrusions. [3]