HOBBS MINERALOGY OF WISCONSIN. 115 



associated in the deposits in the Wisconsin area are cal- 

 cite, smithsonite, galena, cerussite, sphalerite, gypsum, 

 barite, marcasite, pyrite, chalcopyrite, azurite, malachite, 

 and limonite. Hematite, siderite, pyrolusite, hydrozincite, 

 and anglesite have also been reported. As will be shown 

 below it is probable that what has been reported as angle- 

 site is a well crystallized variety of gypsum, or selenite. 

 Some additional minerals, notably amethystine quartz and 

 calamine, are found in the areas of adjoining states, the 

 so-called "calamine" of the Wisconsin mines is, however, 

 not calamine but smithsonite. 



Wisconsin calcites, smithsonite pseudomorphs, and azu- 

 rites, are somewhat widely distributed in cabinets, as are also 

 the galenas from Galena, 111., but I am not aware that any 

 crystallographical study has heretofore been made on any 

 of these minerals. 



CALCITE FROM MINERAL, POINT, LINDEN MINE, MIFFLJN, 



AND GALENA. 



Southern Wisconsin has long been known as a locality 

 for crystallized calcite, and specimens from the region are, 

 therefore, somewhat widely distributed in collections. The 

 best crystals come from the Linden Mine, Mineral Point, 

 Galena, and Mifflin. They are frequently found to be modi- 

 fied, and they show considerable variety in their habits. 

 Without regarding the less important variations, seven 

 distinct types of crystal are observed, four of which are 

 frequently met with and stand in an interesting relation- 

 ship to one another as regards their periods of formation. 

 These types may be distinguished as follows: . 



Type 1. Habit, common scalenohedron R 3 (2131) very 

 much rounded ; modified by R and by other undeterminable 

 faces; color, milk white, brown, or pink, often variegated; 

 opaque; crystals seldom over two inches in length, though 

 larger cleavage pieces are found. Linden Mine and Ga- 

 lena. (See plate 4, fig. 1.) 



