OHDEH vin. PRISMATIC SCHEELIUM-OKE. 887 



Fichtel and Riesengebiirge in Germany. Disseminated 

 through the rocks, it is found at Zinnwald in Bohemia and 

 Saxony and in Cornwall, in beds in granite at Zinnwald, 

 in mica-slate in Galicia, in the Stockwerke it is found at 

 Schlaggenwald in Bohemia, at Altenberg, Geyer, &c. in 

 Saxony, in veins at Ehrenfrieclersdcrrf, Marienberg, Ahen- 

 berg, and other places in Saxony, in Bohemia, but particu- 

 larly in great prefuskm in Cornwall. Tin stream-works 

 are likewise opened in Saxony, and still more so in Corn* 

 wall. The columnar compositions of pyramidal Tin-ore 

 from Mexico and ChiH, are also products of stream-works! 

 The finest and most re'markable simple varieties are found 

 in Cornwall, twins and regular compositions in general in 

 Saxony and Bohemia. Small groupes of black twin-crystals 

 have been lately discovered in the' albite-rock of Chester- 

 field in Massachusetts, and are accompanied by red and 

 green varieties of rhombohedral Tourmaline. 

 5. The pyramidal Tin-ore is' used for extracting, tin-. 



GENUS V. SCHEELIUM-ORE/ 

 1. PRISMATIC SCHEELIUM-OEE. 



Prismatic Wolfram. JAM. Syst. Vol. III. p. 170. Man.- 

 p. 240. Wolfram. Tungstate of Iron. PHILL. p. 255. 

 Wolfram. WERN. Hoffm. H. #. IV. 1. S. 242. Wolf- 

 ram. HAUSM. I. S. 308. Wolfram. LEONH. S. 377. 

 Sche'elin ferrugine'. HAUY. Traite, T. IV. p. 314* 

 Tabl. comp. p. 118. Traite', 2de Ed. T. IV. p. 366. 



Fundamental form. Scalene four-sided pyramid. 

 P = | ll^p | } , 105* 49 r , 105 49^ Inclination 



in the plane of the short diagonal = 0. Vol. 1. 

 Fig. 41. HAUY. 



a : b : c : d = 1 : Jl'333 : 1:0. 



