Granite may have more alkali feldspar, whereas a granite derived from partial melting of metaigneous rocks may be richer in plagioclase. It is on this basis that the modern "alphabet" classification schemes are based. The letter-based Chappell & White classification system was proposed initially to divide granites into I-type (igneous source) granite and S-type (sedimentary sources). Both types are produced by partial melting of crustal rocks, either metaigneous rocks or metasedimentary rocks. M-type granite was later proposed to cover those granites that were clearly sourced from crystallized mafic magmas, generally sourced from the mantle. However, this proposal has been rejected by
Fall River granite a mixture of the flesh red and light green varieties; the former predominating: the quartz is light gray, and the mica, usually black... it works easily and has a lighter and more lively appearance than Quincy granite. The granite quarry industry in Fall River had been established by 1840, employing 30 people, with the rock being transported to places such as Newport, New Bedford, Providence, Bristol, and New York City. Several granite quarries operated in the area in the late 19th century, the largest of which was the Beattie Granite Quarry, located near what is now North Quarry Street, near