Diorite is an intermediate, intrusive igneous rock.  It is the coarsely-crystalline equivalent of andesite, having the same general chemistry & mineralogy.  Many diorites superficially resemble granites, but diorites have little to no quartz, whereas granites have a significant quartz component (otherwise they wouldn't be granites).  The feldspar in diorites is dominantly plagioclase, with a small to negligible potassium feldspar component.





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