APPENDIX. 847 



Subs. 3. — Ferruginous Quartz. 



In amorphous masses, of a deep-red, brown, or yellowish-red 

 color, along the southern shore of Lake Superior. Likewise, 

 crystallized, in very minute hexagonal prisms, terminated by six- 

 sided pyramids, of a reddish color, on the summit and declivities 

 of the Grangje de Terre. 



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Subs. 4. — Prase. 



In the drift of Lake Superior, Its color is a light green and 

 not fully translucent. It possesses a hardness and a lustre inter- 

 mediate between waxy and resinous. 



Subs. 5. — Chalcedony. 



1. Common ChaJcedony. — In globular or reniform masses im- 

 bedded in trap-rock, on the Peninsula of Keweena, Lake Supe- 

 rior. It is found sometimes in association with other quartz 

 minerals. Its color is white or gray, sometimes veined or spotted 

 with red. Also, constituting the interior lining of geodes at the 

 rapids of Eock Island and the River Desmoines. These geodes, 

 on breaking, often present a maramillary surface. In the form 

 of translucent fragments, with a highly conchoidal fracture, among 

 the debris of the shores of Lake Pepin. These fragments possess 

 an extremely delicate texture, color, and lustre. 



2. Cacholong. — Some loose fragments of this mineral exist along 

 the west shore of Lake Michigan, between Green Bay and Chicago. 

 These fragments possess small cavities studded over with very 

 minute and perfect crystals of quartz. 



3. Carnelian. — This mineral occurs in fragments in the debris 

 of Lake Superior ; also, in the amygdaloid ; also, around the 

 shores of the Upper Mississippi. Its color is various shades of 

 red, or j'ellowish red, sometimes spotted or clouded, fully trans- 

 lucent, and occasionally presenting a considerable richness and 

 beauty. Most commonly, the fragments are too small to be ap- 

 plied to the purposes of jewelry. Sometimes it is seen in very 

 regular spheroidal masses, which contain a nucleus of radiated 

 quartz. Some of the specimens would be considered as sardonyx. 



4. Agate. — Is found with the preceding. It is more frequently 

 found in larger masses, in the rock, which are sometimes spher- 



