10 



LARSEN AND STEIGER! MINERALOGIC NOTES 



chalky decomposed rhyolite with here and there a flake of seri- 

 cite, confirms this conclusion. 



The thuringite from the Amethyst vein and the chlorite from 

 the Ridge-Solomon vein are both fusible at about 4 and become 

 magnetic on ignition. The thuringite decomposes in acid with 

 imperfect gelatinization. 



A chemical analysis of thuringite from the Last Chance mine 

 on the Amethyst vein, a few miles above Creede, is given in 

 column 1 of table 2. The material analyzed contained a little 

 admixed quartz. Other analyses of thuringite are given in 

 columns 2 and 3 lor comparison, and in column 4 is given the 

 analysis of the gouge from the Solomon mine, which, as already 



TABLE 2 

 Analyses of Thuringite and Gouge 



1. Thuringite from the Last Chance mine near Creede, Colorado. J. G. Fair- 

 child, analyst. 



2. Thuringite, Harpers Ferry. J. L. Smith, analyst. From Dana's System 

 of Mineralogy, 6th edition, p. 657, analysis 5. 



3. Thuringite, Arkansas. J. L. Smith, analyst. From Dana's System of 

 Mineralogy, 6th edition, p. 657, analysis 7. 



4. Gouge made up largely of chlorite, from the Solomon mine near Creede, 

 Colorado. J. G. Fairchild, analyst. 



