JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. II, NOVEMBER 4, 1912 No. 18 



GEOCHEMISTRY. — Vanadium and chromium in rutile and the 

 possible effect of vanadium on color. Thomas L. Watson, 

 University of Virginia. Communicated by F. W. Clarke. 



Vanadium and chromium are rather widely diffused in very 

 small quantity in a variety 1 of rocks and minerals, especially in ig- 

 neous rocks. Clarke 2 computes the average of 87 determinations 

 of V 2 3 in igneous rocks analyzed in the laboratory of the U. S. 

 Geological Survey to be 0.013 per cent, and for 256 igneous rocks 

 0.05 per cent of Cr 2 3 . In addition to its general presence in 

 small amount in igneous rocks (shown by Hillebrand 3 to be small- 

 est in persilicic rocks and highest in subsilicic rocks), vanadium 

 occurs in many sedimentary and metamorphic rocks and in a 

 variety of minerals. 4 It occurs in some hydrocarbons especially 

 asphaltite from Peru and elsewhere 5 and in some coals (lignite 

 and anthracite), and has been reported in some meteorites, in the 



1 A good summary of the reported distribution of vanadium in rocks and minerals 

 with references is given by Clarke, F. W., Bull. U. S. Geol. Survey, No. 491, 672- 

 678. 1912. See also Moissan, H., Traite de Chimie Mineralogie, 2: 100. 1905; 

 and Thorpe's Dictionary of Applied Chemistry, 1909; Vogt, J. H. L., Zeitschr. 

 prakt. Geol., p. 274. 1899. For the distribution of chromium see Bull. U. S. Geol. 

 Survey, No. 491, 664-666. 1912. 



2 Clarke, F. W., Loc. cit. 



3 Hillebrand, W. F., Amer. Jour. Sci. 6: 209-216. 1898; also see Bull. U. S. Geol. 

 Survey, No. 167, 49-55. 1900. 



4 Hayes, H. H., Proc. Amer. Acad. 10: 294. 1875. 



5 Hewitt, D. F., Vanadium Deposits in Peru, Trans. A. I. M. E. 40: 274-299. 

 1910. 



431 



