290 UNIVERSITY OF VIRGINIA PUBLICATIONS 



pegmatites of granitic composition in North Carolina. According to Pratt* 

 monazite and zircon occur primariljantlie highly pegmatized Carolina gneiss 

 of western North Carolina, and are more abmidant in the pegmatite than in 

 the gneiss. The principal locality in the United States where zircon has 

 heretofore been fomid in commercial quantity is in the vicinity of Zirconia, 

 Henderson County, North Carolina. f It occurs abundantly at this local- 

 itj^ in a pegmatite dike 100 feet wide and traced for I5 miles along the direc- 

 tion of strike N.50°E. The pegmatite penetrates Archaean gneis.^es and 

 is kaolinized to a depth of 40 feet. The zircons are prismatic crystals with 

 pyramidal terminations measuring up to 30 mm. in diameter, of grayish 

 to reddish brown color | and occur mostly in the feldspar. Many tons of 

 zircon have been obtained from this locality. 



Somewhat similar zircon pegmatites, but very much less weathered, 

 occur in the Wichita Mountains, Oklahoma. Sloan§ reports the occurrence 

 of zircon with monazite in pegmatite bodies in Anderson, Greenville, Spar- 

 tanburg, York, and Cherokee counties. South Carolina, and loose in the 

 soil derived from the decay of these masses, associated with a varietj^ of 

 heavy minerals. 



According to Brogger^f zircon is a common mineral in the pegmatite 

 dikes of the Christiania, Norway, region. Zircon and polymignite (zircono- 

 titanate) occur here aiid there in the larvikite pegmatites of the Frederiks- 

 vaern district, and the nepheline syenite pegmatites of the Langesunds- 

 fjord are reported to be rich in zircon." The mineral occurs with biotite, 

 ilmenite, fergusonite, monazite, and yitrium spar in the pegmatite of the 

 Riesengebirge, Silesia, and is a frequent constituent of the granite and syen- 

 ite pegmatites found along the west coast of Greenland,® and in the peg- • 

 matites of Basses-Pyrenees. || 



Mineral Associates.. 



The mineral associates of zircon include a very wide range of species. 

 As a product of crystallization from magmas it is associated with most of 



* Pratt, J. H., Economic paper No. 14, N. C. Oeol. Survey, 1907, pp. 109-120, 123. 

 t Pratt, J. H., Economic paper No. 8, N. C, Geol. Survey, 1904, pp. 40-41. 



I Hidden, W. E. and Pratt, J. H., A?ner. Jour. Sci., 189S, vol. vi, pp. 323-336. 

 § Sloan, B. E., Bull. No. %, S. C. Geol. Survey, series iv, 1908, pp. 129-142. 



If Brogger, W. C, Eruptivgesteine der Kristiania Gebietes, 1894, vol. i. 

 ° Brogger, W. C, Syenitpegm.atitgdnge, 1890, pp. 121-200; Die Mineralien der 

 sudnorwegischen Graniipegmaiitgange , 1906. 

 O Hintze, C, Handbuch der Mineralogie, 1907, p. 1663. 



II Lacroix, Bull. Soc. Min., 1891, vol. 14, p. 394. 



