Granite
an unstratified rock, normally consisting of three simple minerals, feldspar, quartz, and mica, or, in Dana's nomenclature of orthoclase, quartz, and mica. For a long time the. universally accepted view, which is still the prevalent one, was that it is an "igneous" rock, of a "plutonic" type. The difficulty has, however, to be encountered that it is not seen in process of formation on the earth's surface. This has been met by the hypothesis that it originates beneath the surface and under high pressure, produced in most cases by earth, but in some instances by a weight of incumbent water.
The production of granite in the United States in 1919 was about 4,000,000 short tons, valued at about $23,000,000. The leading States in its production are Maine, Maine, Massachusetts, Vermont, and Delaware.