V O L U M E 27, NO. 6, J U N E 1 9 5 5
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Table 111. Comparison of Determinations by X-Ray and Chemical blethods on Various Samples Sample
Thoria, % X-ray Chemical 0.7 9.5 F 4 6.50 4 7 4.4 0 2!? 0.19 0 71 0.78 1 02 0.96 2 1 2.2 2.3 2 0
chemical results. The average per cent difference for the 16 samples with more than 0.776 thoria is 4.770 and the maximum difference is 9.5%.
Difference.
%
hIonazite A 2 1 Alonazite B 6 2 11onazite C 6 8 hpatite 52 (j Magnetic separate 9 0 Carbonate 6 3 Heavy mineral eeparate 4.0 Siliceous rock 1 4 Xenotime 3 3 3 3 n Lignite ash Z,i Monazite from Mount Weathrr 5.8 3.3 Eschynite 0.0 6.4 3.1 Dilute monaziteY 0.97 1.00 3.0 Black sanda 3 li 3.6 0 Weathered vein materialn 1.80 1.68 7.1 Thorianite oren 1 80 1.87 3.7 1%-eatheredvein materiala 4.G 4.2 9.5 a Briquet contains 0.4-gram sample, 0.1 gram TIC1, 1.0 gram AI, 0.5 gram S i c . Counting for apatite is 5.3: for all others, 2.67a or less.
E.;
ACKNOWLEDGMEYT
The authors uish to thank the following members of the U. S. Geological Survey for furnishing both the samples and the chemical analyses: F. S. Grimaldi, Irving hlay, Harry Levine, and >I. I
