Geology of the Pegmatites and Associated Rocks of Maine: Including Feldspar, Quartz, Mica and Gem Deposits

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U.S. Government Printing Office, 1911 - Gems - 152 pages
 

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Page 42 - Washington, Government Printing Office, 1901, pp. 1-180. MENDENHALL, WC A reconnaissance in the Norton Bay region, Alaska, in 1900. In a special publication entitled "Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900," Washington, Government Printing Office, 1901, pp.
Page 13 - SCHRADER, FC, and SPENCER, AC The geology and mineral resources of a portion of the Copper River district, Alaska.
Page 51 - Paper 15. Not issued separately. Copper and upper Chistochina rivers; scale, 1:250,000; by TG Gerdine. Contained in Professional Paper 41. Not issued separately. Copper, Nabesna, and Chisana rivers, headwaters of; scale, 1: 250,000; by DC Witherspoon.
Page 54 - Bulletin 328, 1908, 343 pp. •Investigation of the mineral deposits of Seward Peninsula, by PS Smith. In Bulletin 345, 1908, pp. 206-250. 45 cents. Geology of the Seward Peninsula tin deposits, by Adolph Knopf. Bulletin 358, 1908, 72 pp.
Page 52 - Yukon placer fields, by LM Prindle. In Bulletin 284, 1906, pp. 109-131. Reconnaissance from Circle to Fort Hamlin, by RW Stone. In Bulletin 284, 1906, pp. 128-131. The Yukon-Tanana region, Alaska; description of the Circle quadrangle, by LM Prindle.
Page 53 - Placer mining in the Yukon-Tanana region, by CE Ellsworth. In Bulletin 442, 1910, pp. 230-245. Occurrence of wolframite and cassiterite in the gold placers of Deadwood Creek, Birch Creek district, by BL Johnson. In Bulletin 442, 1910, pp. 246-250.
Page 128 - ... magnesia (in natural cements at least) may be regarded as being almost exactly interchangeable with lime, so far as the hydraulic properties of the product are concerned. The presence of magnesium carbonate in a natural cement rock is then merely incidental, while the silica, alumina, and iron oxide are essential.
Page 126 - ... if the quartz content does not exceed 20 to 30 per cent and if a sufficient quantity of pure feldspar is added to reduce the total percentage of quartz in the ground product to between 15 and 20 per cent. COMMERCIAL AVAILABILITY. Whether it will pay to work a given feldspar deposit depends on a number of factors, chief among which are (1) the distance from railroad or navigable water; (2) the freight rates to principal markets; (3) the quantity and quality of the material available; (4) the cheapness...
Page 127 - The requirements of the potter's trade demand that in general the percentage of free quartz associated with the feldspar used for this purpose shall not exceed 20 per cent in the ground product, and certain potters demand a spar which is nearly pure, containing probably less than 5 per cent of free quartz.
Page 54 - Bulletin 247, 1905, 85 pp. Gold mining on Seward Peninsula, by FH Moffit. In Bulletin 284, 1906, pp. 132141. The Kougarok region, by AH Brooks. In Bulletin 314, 1907, pp. 164-181.

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