APPENDIX. 357 



copper, along the southern shore of Lake Superior, at Ontonagon 

 River, &c. 



2. Steatite. 



At Presque Isle, near Hiver au Mort, Lake Superior, in con- 

 nection with the serpentine formation. Also, at the Lake of the 

 Woods, of a black or very dark color, where it is employed by 

 the Indians in carving pipes. 



3. Asbestos. 



Common Asbestos. — In serpentine and steatite, at Presque Isle 

 Point, Lake Superior. Also, in minute veins, in detached masses 

 of diallage and serpentine rocks, on the west shore of Lake Michi- 

 gan. These veins are no more than a fourth of an inch in width, 

 and the fibres of asbestos occur transversely. They are very 

 flexible, and easily reducible into a flocculent mass. 



f. Barytic Minerals. 



Sulphate of Barttes. 



Lamellar Sulphate of Barytes. — In detached masses, imbedded 

 in diluvial soil, at the mines of Peosta, or Dubuque, on the Upper 

 Mississippi, where it is accompanied by sulphuret of lead, cal- 

 careous spar, &c. Also, at the Mine au Fevre (now Galena), and 

 at the mouth of the Sissinaway River, on the east banks of the 

 Mississippi, between Prairie du Chien and Fort Armstrong. Its 

 colors are white or yellow, and it is frequently incrusted with a 

 thin coat of yellow oxide of iron. It is most commonly opaque. 

 The only translucent specimen seen was procured at Dubuque's 

 mines. 



g. Strontian Minerals. 

 Sulphate of Strontian. 



Foliated Sulphate of Strontian. — At Presque Isle (Wayne's Battle 

 Ground), on the Maumee River, Wood County, Ohio, It occurs 

 in veins and cavities, in compact limestone, most commonly in 

 the form of flattened prisms. Its color is blue, frequently a very 

 light or sky-blue, and the crystals are fully translucent, or even 



