Granite general, descriptive field term for lighter-colored, coarse-grained igneous rocks. Petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite. Granite is nearly always massive (i.e., lacking any internal structures), hard, and tough. These properties have made granite a widespread construction stone throughout human history. The average density of granite is between , its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6·10 Pa·s. The melting temperature of dry granite at ambient pressure is ; it is strongly reduced in the presence of water, down to
Granite Railway past, many persons were injured — and some killed — while diving into the flooded abandoned quarries from great heights. The Department of Conservation and Recreation maintains the Quincy Quarries Reservation, which has facilities for rock climbing, and trails connecting the remains of the Granite Railway. Granite Railway The Granite Railway was one of the first railroads in the United States, built to carry granite from Quincy, Massachusetts to a dock on the Neponset River in Milton. From there boats carried the heavy stone to Charlestown for construction of the Bunker Hill Monument. The Granite Railway is popularly termed the