Granite and feldspar. The term "granitic" means granite-like and is applied to granite and a group of intrusive igneous rocks with similar textures and slight variations in composition and origin. These rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende) peppering the lighter color minerals. Occasionally some individual crystals (phenocrysts) are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is known as a granite porphyry. Granitoid is a
Fall River granite of the underlying granite is the Hixville Fault near Dartmouth, Massachusetts. From a distance, the rock exhibits a distinctive tan-gray color. Viewed up close, it is more pink. The granite is very hard and durable, but cannot be polished very well. As a result, its appearance on a building is almost always somewhat rough, rather than the sharp lines of other types of building stone. Edmund Hitchcock, of the 1841 Geological Survey of Massachusetts gave the following description of the granite: But no rock can be finer for architectural purposes than the granite of Troy...The feldspar of this rock is