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Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and sometimes pyroxene.The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite.
Quartz diorite from Dúbrava, Nízke Tatry Mountains, Slovakia. Quartz diorite is an igneous, plutonic rock, of felsic composition, with phaneritic texture. Feldspar is present as plagioclase (typically oligoclase or andesine) with 10% or less potassium feldspar. Quartz is present at between 5 and 20% of the rock.
The remnants of a very large diorite statue in the British Museum may be a representation of Gudea, but this cannot be determined with certainty. What remains of the statue is 1.5 m (4 ft 11 in) high (and weighs over 1,250 kg (2,760 lb)), meaning that if it were fully reconstructed the statue would be well over 3 m (9.8 ft) high and the largest ...
Napoleonite is a variety of diorite which is characterized by orbicular structure. The grey matrix of the stone has the normal appearance of a diorite, but contains many rounded lumps 1 or 2 inches in diameter, which show concentric zones of light and dark colors.
Diorite – Igneous rock type Napoleonite, also known as corsite – Variety of diorite with orbicular structure; Dunite – Ultramafic and ultrabasic rock from Earth's mantle which is made of the mineral olivine; Essexite – Igneous rock type; Foidolite – Igneous rock rich in feldspathoid minerals; Gabbro – Coarse-grained mafic intrusive rock
Examples of phaneritic igneous rocks are gabbro, diorite, and granite. Porphyritic textures develop when conditions during the cooling of magma change relatively quickly. The earlier formed minerals will have formed slowly and remain as large crystals, whereas, sudden cooling causes the rapid crystallization of the remainder of the melt into a ...
The Crazy Mountains have assemblages of diorite, gabbro, and peridotite as a result from laccoliths, sills and dikes. [7] This region's extensive subcontinental mantle is similar to mid-ocean ridge and ocean island basalt sources. [8]
However the current IUGS classification defines tonalite as having greater than 20% quartz, while quartz diorite varies its quartz content from 5 to 20%. [ 1 ] The name is derived from the type locality of tonalites, adjacent to the Tonale Line, a major structural lineament and mountain pass, Tonale Pass , in the Italian and Austrian Alps .