Quartz monzonite is an intrusive, felsic, igneous rock that has an approximately equal proportion of orthoclase and plagioclase feldspars.

[1] The term adamellite was originally applied by A. Cathrein in 1890 to orthoclase-bearing tonalite (likely a granodiorite) at Monte Adamello, Italy, in 1890, but later came to refer to quartz monzonite.

[3] In the White Mountains and western highlands of New Hampshire, the Kinsman Quartz Monzonite is an extensive formation that underlies Kinsman Mountain, parts of Franconia Notch, Mount Cardigan, and Mount Sunapee.

[citation needed] Quartz monzonite extracted from a quarry in Little Cottonwood Canyon was used to build several buildings in Salt Lake City, Utah, including the Church of Jesus Christ of Latter-day Saints' Salt Lake Temple, Church Administration Building, and Conference Center, as well as the Utah State Capitol.

[citation needed] The large boulders of Joshua Tree National Park in southern California are quartz monzonite.