536 APPENDIX. 



25. Zeolite. Kadiated. Lake Superior. This mineral con- 

 sists 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. AsBESTUS. Presque Isle, Lake Superior. In the serpentine 

 formation. 



27. HoENBLENDE. Yery abundant as a constituent of the pri- 

 mitive rocks on the L'pper 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, Eiver 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 lY. Ores and Metals. 



34. Native copper. West side of Keweena Point, Lake Su- 

 perior, Imbedded in a vein with carbonate of copper, and copper 

 black, in the trap-rock, 



35. Copper black. With the preceding. 



86. 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. 



