APPENDIX. 535 



11. Amethyst. "With the preceding. Also, at tlie Pic Bay, 

 and at Gargontwa, north shore of Lake Superior, in the trap-rock, 

 in perfect crystals, of various intensity of color. 



12. Chalcedony. Keweena Point, Lake Superior. In globu- 

 lar or orbicular masses, in amygdaloid rock. Often, in detached 

 masses along the shores. 



13. Carnelian. With the preceding. 



14. HoRNSTONE. In detached masses, very hard, on the shores 

 of Lake Superior. Also, at Dodgeville, Iowa County, Mich. Ter., 

 in fragments or nodular masses in the clay soil. 



15. Jasper. In the preceding locality. Common and striped, 

 exceedingly difficult of being acted on by the wheel. Not ob- 

 served in situ. 



16. Agate. Imbedded in the trap-rocks of Lake Superior, 

 and also detached, forming a constituent of its detritus. Vari- 

 ously colored. Often made up of alternate layers of chalcedony, 

 carnelian, and cacholong. Sometimes zoned, or in fortification 

 points. Specimens not taken from the rock are not capable of 

 being scratched by quartz or flint, and are incapable of being 

 acted on by the file ; consequently, harder than any of the described 

 species. 



17. Cyanite. Specimens of this mineral, in flat, six-sided 

 prisms, imbedded in a dark primitive rock, were brought out 

 from Lac du Flambeau outlet, where the rock is described as 

 existing in situ. The locality has not been visited, but there are 

 facts brought to light, within the last two or three years, to justify 

 the extension of the primitive to that section of country. 



18. Pitchstone. a detached mass of this mineral, very black 

 and lava-like, was picked up in the region of Lake Superior, 

 where the volcanic mineral, trachyte, is common among the rolled 

 masses. Neither of these substances have been observed in situ. 



19. Mica. Huron Islands, Lake Superior. In granite. 



20. Schorl. Common. Outlet of Lac du Flambeau. Also, 

 in a detached mass of primitive rock at Green Bay. 



21. Feldspar. Porcupine mountains. Lake Superior. 



22. Basalt. Amorphous. Granite Point, Lake Superior. 



23. Stilbite. Amygdaloid rock, Keweena Point, Lake Supe- 

 rior. 



24. Zeolite. Mealy. With the preceding. 



