Watson and Watkins — Rutile and Gyanite. 195 



Art. XXII. — Association of Buttle and Cyanite from a 

 New Locality* by Thomas L. Watson and Joel H. 

 Watkins. 



Introduction. 



The occurrence of rutile in association with cyanite is known 

 from a number of localities in this and foreign countries, f but 

 the literature contains scarcely more than the mere statement 

 that the two minerals are observed in association. The known 

 localities in the United States in which rutile and cyanite 

 occur together are Graves Mountain, Lincoln County, Georgia, 

 and Crowder and Clubb mountains, Gaston County, North 

 Carolina. The European localities include Horrsjoberg and 

 Dicksberg, Sweden, and near Petschau, Bohemia. In Brazil, 

 Derby % has described a cyanite schist occurring at Serro do 

 Gigante composed mainly of cyanite, chlorite, sericite, quartz, 

 and rutile, with an analysis by Hillebrand, which shows 4 # 93 

 per cent Ti0 2 . The occurrence of rutile in these localities is 

 of more scientific interest than of commercial value. 



This paper describes briefly field observations made in a 

 small area of metamorphic crystalline rocks, containing rutile 

 and cyanite in intimate association, and results of microscopic 

 study of thin sections of specimens collected from the area. 

 The area lies 12 miles northwest of Charlotte Courthouse, in 

 the extreme northwest corner of Charlotte County, Virginia. 

 The chief object of these notes is to direct attention to the 

 mode of occurrence and relations of rutile and cyanite in this 

 locality, and to note the manner of alteration of the cyanite, 

 which is pronounced and we believe of interest. Cyanite is 

 more abundant than rutile, and the latter is only of scientific 

 interest in the Charlotte County area. 



Lithologic Characters. 



The accompanying map, fig. 1, comprises a very small area 

 in the extensive belt of metamorphic crystalline schists, desig- 

 nated pre-Cambrian in age on the recent geologic map§ of 

 Virginia. Within the area mapped two types of the schist are 

 recognized in their principal differentiated parts, but are 

 regarded as probable variations of a single type, since they 

 appear to grade into each other in the field, and with the excep- 



* The discovery of rutile in the area described in this article was made by 

 the junior author, who has supplied the field notes and map. 



t Dana, E. S. A System of Mineralogy, 1900, pp. 501, 799. Hintze, C. 

 Handbuch der Mineralogie, 1906, p. 1595 ; 1907, pp. 1617-1619. 



X Derby, O. A. This Journal, vol. vii, p. 343, 1899. 



§ Geological map of Virginia. Virginia Geological siirvey, 1911. 



