APPENDIX. 345 



Gros Point, along the west shore of Lake Michigan, between Mil- 

 waukie and Chicago, 



Ochrey red oxide of iron occurs on the shores of Big Stone 

 Lake, at the source of the St. Peter's Eiver. A large spring rises 

 from a level, dry plain, a few feet beyond which the mineral 

 occurs. The Indians, who employ it as a pigment, take it up 

 with their knives. The stratum is about eight inches thick, but 

 just below the surface it is mixed with common earth. The spring 

 of water is pure and unadulterated. 



5. Silver. 



The belief in the existence of silver ore in the region of the 

 lakes, and particularly on Lake Superior, seems to have early 

 prevailed. So much confidence was placed in the reports of its 

 existence, that Henry tells when a company was formed in Eng- 

 land for exploring the copper mines of Lake Superior (a. d. 1771), 

 they were impelled to the search more from an expectation of the 

 silver, which it was hoped would be found in connection with it, 

 than from the copper.* 



b. SilicioKS Minerals. 



1. Quartz. 



This interesting species being distributed in its numerous va- 

 rieties throughout the region visited, I shall confine my notices 

 to a few localities. 



Subs. 1. — Common Quartz. 



Occurs in the form of large water- worn masses along the shores 

 of Lakes Huron, Michigan, and Superior. Also, in veins in the 

 granite of Lake Superior, and in the argillite of St. Louis River. 

 These localities all consist of the opaque varieties, with a slight 



* This metal has subsequently (namely, in 1844) been found to constitute a per- 

 centage in the native copper of the Eagle River mines of Lake Superior. Traces of 

 it were found in a mass of native copper found on the shores of Keweena Lake, by 

 Mr. Moliday, in 1826. A mass of pure silver was discovered in a boulder in the 

 drift of Lake Huron, west of White Rock, in 1824. These discoveries induce the 

 belief that this element will be found to be extensively present in the eventual 

 metallurgic operations of the Lake Superior basin. 



