114 BULLETIN OF THE UNIVERSITY OF WISCONSIN. 



evolved and the iron is oxidized. The mineral is locally- 

 supposed to be silver and the locality is referred to as the 



"silver mine." 



Crystallized Calcitefrom Madison. — In the extensive quarries 

 in calcareous sandstone which are located just west of the 

 city of Madison and which belong to the Lower Magnesian 

 formation, are occasionally found druse crystals of calcite. 

 A specimen collected from this locality exhibits crystals of 

 three to four milimetres diameter lining a small cavity. 



Fig. 3. — Calcite from Madison. 



These crystals have a yellowish tint and are somewhat 

 translucent. The faces are considerably rounded, so as to 

 be unfit for measurement, but the forms can be easily de- 

 termined to be — iR (0112) and R (1010), the latter very 

 small. Another specimen is made up of crystals vary- 

 ing from 1-2 ""■ in diameter bounded by the form — ^R. 

 Still another is bounded by R, goR and a scalenohedron. 

 Still another specimen, apparently dropped on the Univer- 

 sity Drive by the quarry teams, is bounded by OP, R, — ^li, 

 and — 2R. 



THE CRYSTALLIZED MINERALS FROM THE CAVITIES IN THE 

 GALENA LIMESTONE OF SOUTHERN WISCONSIN. 



The lead and zinc ore region of the Upper Mississippi 

 valley includes portions of Wisconsin, Illinois, Iowa, and 

 Missouri. In Wisconsin the mines are now worked chiefly 

 for zinc, which is obtained very largely from a porous va- 

 riety of smithsonite colored brown by limonite, and known 

 locally as drij hone or dry bone ore. This material is mainly 

 utilized for the manufacture of zinc paint. At Shullsburg, 

 where there is at present the greatest activity, black jack 

 is the principal ore and is mined for spelter. The minerals 



