158 APPENDIX. 



11. Amethyst. With the preceding. Also, at the Pic Bay, and 

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

 fect crystals of various intensity of color. 



12. Chalcedony. Keweena Point, Lake Superior. In globular 

 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 frag- 

 ments 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 observed 

 in situ. 



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

 detached, forming a constituent of its detritus. Variously colored. 

 Often made up of alternate layers of chalcedony, carnelian, and cacho- 

 long. Sometimes zoned, or in fortification points. Specimens not ta- 

 ken 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 im- 

 bedded in a dark primitive rock, were brought out from Lac du Flam- 

 beau outlet, where the rock is described as existing in situ. The localiy 

 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 sec- 

 tion 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 vol- 

 canic 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 Superior. 



24. Zeolite. Mealy. With the preceding. 



25. Zeolite. Radiated. Lake Superior. This mineral consists 

 of fibres, so delicate and firmly united as to appear almost compact, ra- 

 diating from a centre. Some of the masses produced by this radiation, 

 measure 2.5 inches in diameter. They are of a uniform, pale, yellow- 

 ish red. This mineral has not been traced in situ, being found in de- 

 tached masses of rock, and sometimes as water-worn portions of radii. 

 Its true position would seem to be the trap rock. 



26. Asbestus. Presque Isle, Lake Superior. In the serpentine 

 formation. 



27. Hornblende. Very abundant as a constituent of the primitive 

 rocks on the Upper Mississippi, and in the basin of Lake Superior. Of- 

 ten in distinct crystal . 



