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.
These two minerals (35 and 36) characterize the trap rock of the peninsula of Keweena, Lake Superior, from Montreal Bay, extending to, and around its extremity, west, to Sand-hill Bay. The entire area may be estimated to comprise a rocky, serrated coast of about seventy-five miles in length, and not to exceed seven or eight miles in width. The principal veins are at a point called Roche Verd, and along the coast which we refer to as the Black Rocks. At the latter, native copper is one of the constituents of the vein.