Granite pegmatite. Grafton field. Hosted by muscovite-sillimanite-staurolite schist. Located on Isinglass Mountain. First commercial
quarry in U.S. (Often cited as 1803, but published records seem to suggest a few years later than that date). Mined for
as well. feldspar mining was intermittent and was active in the mid-1960s, ending by about 1969.
Noted for its excellent vista views and steep dumps with tunnels and galleries into the granite pegmatite. Collecting is permitted after paying a fee ($25 per adult in 2011).
specimens from this locality was announced by Benjamin Shaub in 1936: "Recent work in mining for feldspar at the Ruggles' pegmatite has exposed numerous uranium-bearing ... minerals." The very first specimens were apparently collected by Ray and Alvin Schortmann who lived not far from Ben Shaub in Northampton, MA (B. Shaub, pers. comm., 1989). The abundance of gummite was one of the factors which influenced the Schortmann brothers to start a mineral business, beginning about 1938, that lasted for about 25 years.
72 entries listed. 46 valid minerals. 15 erroneous literature entries.
Sterrett, D. (1914). Some deposits of Mica in the United States (USGS Bulletin 580-F), pp. 80-81.
Shaub, Benjamin M. (1937): Age of the
Uraninite from the Ruggles Mine, Grafton Center, New Hampshire (Science 86:156).
Shaub, Benjamin M. (1938): The Occurrence, Crystal Habit, and Composition of the
Uraninite from the Ruggles Mine, near Grafton Center, New Hampshire (American Mineralogist 23:334-341).
Frondel, Clifford (1950): Sudies of Uranium Minerals (I):
Parsonsite and
Randite (American Mineralogist 35:235-250)
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: 876, 914, 986.
Cameron E.N.; Larabee, D.M.; McNair, A.H.; Page. J.J.; Stewart, G.W.; Shainin, V.E. (1954): Pegmatite Investigations 1942-1945, New England. (USGS Prof Paper 255:1-352.)
Tilden, Paul M. (1955) America's First Mica Mine? (Rocks and Minerals 30:499-500).
Morrill, P. (1960), New Hampshire Mines and Mineral Localities.
Bjareby, Gunnar (1965): Fifty Years of Mineral Collecting, Part 7 (Rocks & Minerals 40:491-493).
Gregory, G. (1971), The Ruggles Feldspar - Mica Mine, Grafton, New Hampshire (Rocks & Minerals 46:12-15)
Sweeney, Harry M. (1975), Field Trip: New Hampshire: The Treasures of Ruggles Mine (Rock & Gem 5(2):59-61).
Cushing, Kenneth R. (1992). Isinglass, Timber, and Wool: A History of the Town of Grafton, N.H. 1761-1992.
Korzeb, Stanley L.; Foord, Eugene E. and Lichte, Frederick E. (1997): The chemical evolution and paragenesis of uranium minerals from the Ruggles and Palermo granitic pegmatites, New Hampshire (Canadian Mineralogist 35:135-144).
Foord, Eugene E.; Korzeb, Stanley L.; Lichte, Frederick E.; and Fitzpatrick, Joan J. (1997): Additional Studies on Mixed Uranyl-Oxide Hydrate Alteration Products of
Uraninite From the Palermo and Ruggles Granitic Pegmatites, Grafton County, New Hampshire (Canadian Mineralogist 35:145-151).
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