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 observed in sitû.
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 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 sitû. 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 sitû.
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.