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 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, radiating from a centre. Some of the masses produced by this radiation, measure 2.5 inches in diameter. They are of a uniform, pale, yellowish red. This mineral has not been traced in situ, being found in detached masses of rock, and sometimes as water-worn portions of radii. Its true position would seem to be the trap rock. 26. ASBESTOS. 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. Often in distinct crystals. 28. DIALLAGE, GREEN. Lake Superior. In detached masses, connected with primitive boulders. _Harder_ than the species. 29. SERPENTINE, COMMON. Presque Isle, Lake Superior. 30. SERPENTINE, PRECIOUS. With the preceding. Color a light pistachio green, and takes a fine polish. Exists in veins in the common variety. 31. PSEUDOMORPHOUS SERPENTINE. With the preceding. This beautiful green mineral constitutes a portion of the veins of the precious serpentine. Its crystalline impressions are very distinct. 32. ARGILLITE. River St. Louis, northwest of Lake Superior. Nearly vertical in its position. CLASS III. _Combustibles._ 33. PEAT. Marine sand formation composing the shore of Lake Superior, between White-fish Point and Grand Marrais. Also, on the island of Michilimackinac. CLASS IV. _Ores and Metals._ 34. NATIVE COPPER. West side of Keweena Point, Lake Superior. Imbedded in a vein with carbonate of copper, and copper black, in the trap rock. 35. COPPER BLACK. With the preceding. 36. CARBONATE OF COPPER, GREEN. With the preceding.