Crossword clues for diorite
The Collaborative International Dictionary
Diorite \Di"o*rite\, n. [Cf. F. diorite. See Diorism.] (Min.) An igneous, crystalline in structure, consisting essentially of a triclinic feldspar and hornblende. It includes part of what was called greenstone.
Wiktionary
n. (context rock English) A grey intrusive igneous rock composed mostly of plagioclase feldspar, biotite, hornblende and/or pyroxene.
WordNet
n. a granular crystalline intrusive rock
Wikipedia
thumb|upright=1.4|Diorite classification on QAPF diagram
Diorite is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite. Diorite is usually grey to dark-grey in colour, but it can also be black or bluish-grey, and frequently has a greenish cast. It is distinguished from gabbro on the basis of the composition of the plagioclase species; the plagioclase in diorite is richer in sodium and poorer in calcium. Diorite may contain small amounts of quartz, microcline, and olivine. Zircon, apatite, titanite, magnetite, ilmenite, and sulfides occur as accessory minerals. Minor amounts of muscovite may also be present. Varieties deficient in hornblende and other dark minerals are called leucodiorite. When olivine and more iron-rich augite are present, the rock grades into ferrodiorite, which is transitional to gabbro. The presence of significant quartz makes the rock type quartz-diorite (>5% quartz) or tonalite (>20% quartz), and if orthoclase ( potassium feldspar) is present at greater than 10 percent, the rock type grades into monzodiorite or granodiorite. A dioritic rock containing feldspathoid mineral/s and no quartz is termed foid-bearing diorite or foid diorite according to content.
Diorite has a phaneritic, often speckled, texture of coarse grain size and is occasionally porphyritic. Orbicular diorite shows alternating concentric growth bands of plagioclase and amphibole surrounding a nucleus, within a diorite porphyry matrix.
Diorites may be associated with either granite or gabbro intrusions, into which they may subtly merge. Diorite results from the partial melting of a mafic rock above a subduction zone. It is commonly produced in volcanic arcs, and in cordilleran mountain building, such as in the Andes Mountains, as large batholiths. The extrusive volcanic equivalent rock type is andesite.
Usage examples of "diorite".
The remaining rocks from here are richer in lime and iron, and show a series of gradual transitions from micacious granite, through grano-diorite to quartz diorite, with considerable quantities of dark mica, and green hornblende.
Scores of beautiful vases of alabaster, breccia, marble, and soapstone, wrought in some cases to the thinness of a modern china cup, suggest at once the protodynastic Egyptian bowls of diorite and syenite, and show that if the Cretan took the idea from Egyptian models, he was not behind his master in the skill with which he carried it out.
On various sites in the palace at Knossos there have been found stone vessels of diorite, syenite, and liparite, exquisitely wrought.
Egypt is afforded by the fact that vases of Proto-Dynastic Egyptian form in diorite and syenite were discovered in the south and east quarters of the palace at Knossos.
It is made of a remarkable variety of porphyritic diorite that resembles breccia.
Under the category of anomalies, West made specific reference to the bowls carved out of diorite and other hard stones described in Part VI.
Scores of beautiful vases of alabaster, breccia, marble, and soapstone, wrought in some cases to the thinness of a modern china cup, suggest at once the protodynastic Egyptian bowls of diorite and syenite, and show that if the Cretan took the idea from Egyptian models, he was not behind his master in the skill with which he carried it out.
Most of the tombstones were of black Swedish granite or diorite, rough hewn on the back and sides and polished in front.
Meanwhile Sister Gertrude had joined the other nurses and I passed around some candy which, in addition to twenty pounds of brown sugar, we had been given for a diorite slab.
I saw them entombed with blocks of diorite and granite pressed against their very bodies in an underground crypt, only their heads and their necks free.