28 ' GEOLOGICAL SURVEY OF WISCONSIN. 



II. SULPHIDS, AlWENIDS, ETC. 



Galenite (Sulphuret of Lead). Extensively mined in the southwestern counties of the 



state. Occurs in small quantities in many other localities. 

 Sphalerite (Blende, Blackjack). Abundant and now extensively mined in the lead 



region. 



Chalcocite (Sulphuret of Copper). At Mineral Point, and other places. 

 Niccolite (Arsenical Nickel). Found in very small quantities in Douglas county, 1873. 

 Pyrite (Cubical Iron Pyrites). At Mineral Point, etc. 

 Chalcopyrite (Copper Ore). At Mineral Point, Mt. Sterling and other places, but not 



in workable quantity. 

 Marcasite (Iron Pyrites, Mundig). With ores of lead and zinc in the lead region; 



masses in drift clay near Lake Michigan, and elsewhere. 

 Tetrahedrite (Gray Copper Ore). Left Hand River, Douglas county. (Owen.) 



III. OXYGEN COMPOUNDS. 



Cuprite (Red Copper Ore). Left Hand River, Douglas county. (Dana.) 

 Water. Natural waters in the Archaean and Sandstone regions are usually soft and nearly 

 pure; in other portions of the state, hard, or containing lime and magnesia from the 

 limestones. At Sparta, Waukesha, etc., the water of certain springs and wells is 

 found to possess medicinal virtues. At Fond du Lac, Sparta and Watertown, the 

 iron tubes through which the water flows become highly magnetic. 



Hematite (Red and Specular Iron Ore). Iron Ridge, Hartford, Depere, etc., in small 

 grain; flax seed ore. Used with Lake Superior ores at Milwaukee and other places. 

 Penokee Iron Range, Ashland county, Wood county, etc. 



Menaccanite (Titanic Iron Ore). In email quantities near Baraboo, Sauk county. In 

 trap rocks, Lake Superior. (Owen.) 



Magnetite (Magnetic Iron Ore). Penokee Iron Range, Ashland county, in great abund- 

 ance; also at Black River Falls, Jackson county, and other places. It is found La 

 the form of sand on the shores of the great lakes. 



Limonite (Brown Iron Ore). Ironton, Sauk county, supplying an iron furnace. In lees 

 quantities at various places, resulting from the decomposition of inarcasite. Bog 

 ore in Wood county and elsewhere. 



Wad (Oxide of Manganese). In small quantities in the lead region, and other places; 

 also the variety asbolite or earthy cobalt. 



Quartz. Crystalized quartz is found in various places. In the form of grains it con- 

 stitutes the sandstones, often pure and white. Its varieties, amethyst, carnelian, 

 jasper, chert, etc., are often found. Quartzite occurs in extensive ridges among the 

 Archaean rocks. 



Amphibole (Hornblende, etc.). Abundant in the Archaean rocks. Variety, tremolite a,t 

 Lac de Flambeau. (Norwood.) 



Garnet. Lac de Flambeau river, four miles above the mouth, and other places in 

 Archaean rocks. (Norwood.) 



Epidote. Associated with copper ores in Ashland and Douglas counties. 



Phlogopite (Rhombic Mica). On the Eau Claire river, four miles above the falls, in 

 large plates. (Dr. Littel.) 



Wemerite (Scapolite). Twin Falls, of the Menomonee River of Green Bay. (Fester 

 & Whitney.) 



Labradorite. An ingredient of trap-rocks; upper rapids of the Bois Brule river of Lake 

 Superior. (Owen.) 



Albite (White Feldspar). Common in boulders of Archsean rocks. 



Orthodase (Potash Feldspar). Common in Archaean rocks. By decomposition forms 

 Kaolin (Potter's Clay). 



