COMPOSITION OF FERBERITE AND OTHER MEMBERS OF SERIES. 33 

 the wolframite series Continued. 



analysis shows also CuO, 1.34; "Ta20 5 , approximately 1.50, and Cb 2 O 5 , 0.70, judging 

 from density of oxides. " The quantity of tantalic and columbic pentoxides indicated 

 is unusually high. The excess W0 3 shown seems to be combined with part of the 

 CuO to form a hydrous copper tungstate new to science. Work is now being under- 

 taken on this mineral. Part of the copper is probably combined with the SiO 2 as 

 chrysocolla. 



79. Ferberite from the Sierra Almagrera, southern Spain. Liebe, K. L. T., Ein 

 neuer Wolframit; ein Beitrag zur Mineral-Chemie : Neues Jahrb., 1863 p. 645,. The 

 analysis also shows A1 2 3 , 1.15; limonite, 1.39; SnO 2 , 0.14; G1O, trace. The analysis 

 as given follows Dana's recalculation after subtracting the limonite (System of 

 Mineralogy, p. 985). The specific-gravity determination is stated to have been 

 made by Breithaupt. 



80. Ferberite from Kootenay Belle mine, Salmo, British Columbia. Walker, T. L., 

 Report on the tungsten ores of Canada: Canadian Dept. Mines, Mines Branch, p. 38, 

 1909. 



81. Ferberite from the American Tungsten Co.'s mine, Hill City, S. Dak. Analysis 

 made at the South Dakota School of Mines. Quoted by C. H. Fulton in a private 

 report on the mine. Traces of Sn0 2 and S were found. If the quantities given are 

 otherwise correct, it seems probable that a part of the substance determined as "SiO 2 " 

 is really CaO; hence the excess of WO 3 . 



82. Ferberite from the Sierra Almagrera, southern Spain. Rammelsberg, C. F., 

 Ueberdie chemische Zusammensetzung des Ferberits: K. preuss. Akad. Wiss. Ber- 

 lin Monatsber., p. 175, 1865. 



83. Ferberite from Adun-Tschilon, Siberia. Average of four analyses. Beck, W., 

 and Teich, N., Ueber Wolfram und Scheelit aus Fundorten Russlands: Russ.-k. 

 mineral. Gesell. St. Petersburg Verh., 2d ser., vol. 4, p. 315, 1869. 



84. Ferberite from Ivigtut, Greenland. Analysis by Chr. Christensen. Boggild, 

 O. B., Mineralogia Greenland (Ssertryke af Meddelelser om Gronland, vol. 32): Min- 

 eral, and Geol. Mus. Univ. Copenhagen, Contr. to Mineralogy No. 6, p. 182, 1905. 



85. Ferberite from Last Chance, Boulder County, Colo. Analysis by J. B. Ekeley. 

 George, R. D., The main tungsten area of Boulder County, Colo.: Colorado Geol. 

 Survey First Rept., p. 42, 1909. 



35659 Bull. 58314 3 



