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Rhomb porphyry is a volcanic rock with gray-white large porphyritic rhombus-shaped phenocrysts of feldspar (commonly anorthoclase) embedded in a very fine-grained red-brown matrix. The composition of rhomb porphyry places it in the trachyte–latite classification of the QAPF diagram. [12]
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 ...
Andesite porphyry from summit of O'Leary Peak. This is an extrusive porphyritic rock, as the pink (and black) phenocrysts are clearly visible, in contrast to the grey groundmass with its microscopic crystals.
Porphyry copper deposits represent an important resource and the dominant source of copper that is mined today to satisfy global demand. [6] Via compilation of geological data, it has been found that the majority of porphyry deposits are Phanerozoic in age and were emplaced at depths of approximately 1 to 6 kilometres with vertical thicknesses on average of 2 kilometres. [6]
Porphyria / p ɔːr ˈ f ɪr i ə / is a group of disorders in which substances called porphyrins build up in the body, adversely affecting the skin or nervous system. [1] The types that affect the nervous system are also known as acute porphyria, as symptoms are rapid in onset and short in duration. [1]
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 ...
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Porphyry deposits account for most of the copper and molybdenum world production, 60 and 95 percent of its supply respectively. [1] Porphyry-type ore deposits form in hydrothermal fluid circulation systems developed above and around high-level, subvolcanic felsic to intermediate magma chambers and/or cooling plutons. The ore is temporally and ...