Granite pegmatite, Alstead field. Located near the village of South Acworth.
Beryl Mountain was known in the 1820's and a famous expedition went there in 1829, led by the young Charles Upham Shepard, with Edward Hitchcock and others. By 1837, Francis Alger, noted amateur mineralogist and editor of Phillips' Elementary Treatise on Mineralogy (4th edition, 1844), had found giant beryl crystals (to 4 feet by 5 inches across one prism face = 1.22 m x 12.5 cm)and at that time were regarded as world record size. The longest reliably reported beryl from this locality is 5 feet (Cameron et al., 1954), although some reports of larger crystals (to 6 a 1 feet = 2 x 0.3 meters) appear unsubstantiated.
A beryl locality that produced a small tonnage of beryl ore (about 20 tons of beryl).
References:
Holden, Edward F. (1918): Famous Mineral Localities: Beryl Mountain, Acworth, New Hampshire (American Mineralogist 3:199-200).
US Bureau of Mines Report of Investigation 4410 (1948).
Rocks & Minerals (1949): 24: 594-596.
Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 941.
Hurlbut, C.S., Jr. (1952) Wardite from Beryl Mountain, New Hampshire. American Mineralogist 37, 849-852. (Erroneously labeled specimen from the Palermo #1 Pegmatite. C. Hurlbut, pers. comm., 1992).
Cameron et al. (1954) Pegmatite Investigations 1942-1945 New England. USGS Professional Paper 255.
Page & Larrabee (1962) Beryl Resources of New Hampshire, USGS Professional Paper 353.
Roy, Walt (1965) Beryl Mountain, South Acworth, New Hampshire. Rocks and Minerals: April 1965.
Januzzi, R.E. and Seaman, David M. (1976) Mineral Localities Of Connecticut and Southern New York State and Pegmatite Minerals of the World.
King, V., 2006, In Search of Francis Alger, a Boston Mineralogist, Journal of the Geo-Literary Society, v. 21, p. 4-14.
