GEOLOGY. 297 



the masses being translucent and nearly transparent, and resembling 

 the "asparagus-stone" variety of the mineral. The more compact 

 and opaque masses frequently cleave into hexagonal prisms, some of 

 them having lateral planes three inches wide. Rhombohedrons 

 resulting from cleavage are not uncommon. 



Brown Tourmaline Beautiful transparent crystals of brown tour- 

 maline occur disseminated in the massive and concretionary phos- 

 phorite at the " eupyrchroite " locality, Crown-point, Essex Co., 

 N. Y. ; terminated crystals are rare, but the few found are highly 

 modified, and are crystallographically similar to the crystals from 

 Gouverneur, N. Y., described and figured by Rose. (See Dana's 

 Mineralogy, p. 136.) The color is a light clove-brown, and the 

 crystals exhibit dichroisin. Specimens cut and polished have much 

 beauty as gems. 



Red Zinc Oxide. Fine cabinet specimens of lamellar red zinc oxide 

 can be obtained at the zinc mine, Stirling Hill, Sussex Co., N. Y. 

 The lamellar masses are disseminated in the highly crystalline lime- 

 stone which has frequently a delicate pink hue and translucent, 

 cleaving readily into large rhombohedrons ; the contrast between the 

 red zinc and the gangue adds greatly to the beauty and mineralogical 

 value of these specimens. These distinct nodules of oxide are found 

 at the junction of the vein of red zinc ore and the limestone, but the 

 oxide is free from any admixture with Franklinite crystals ; good 

 crystalline specimens of Franklinite are now very rare at the mine. 



Fluor-Spar Locality. Shawneetown, Gallatin Co., 111., has long 

 enjoyed a reputation among American mineralogists as a locality for 

 fluor-spar. Having had occasion, a few months since, to visit the 

 southern portion of Illinois, I explored this locality. It was found, 

 however, that the fluor-spar did not occur, as reputed, at Shawnee- 

 town, but ten to fifteen miles farther down the Ohio, and a half a mile 

 to a mile north of the river. 



The fluor occurs in the carboniferous limestone, it forms numerous 

 veins, many of which are from ten to twenty feet in thickness. It is 

 highly crystalline, and often very fetid ; beautiful crystallized speci- 

 mens are found in pockets in the veins, which are sometimes entirely 

 colorless, frequently of a blue, a violet, or a pink tint, and more 

 rarely of an emerald-green. The localities have been quite exten- 

 sively worked for lead, which, under the form of galena, is associated 

 with the fluor. The amount of galena is quite considerable, although 

 no regular vein has as yet been found ; it is somewhat argentiferous, 

 yielding, on an average of several specimens examined, about four 

 ounces of silver to the ton. The mining of these veins has devel- 

 oped, besides some fine crystallizations of fluor, as a compact variety 

 in which the associated galena also has the compact structure. An 

 immense amount of a remarkably fine quality of fluor-spar could be 

 obtained from these veins should there be a demand for it in the arts. 

 Com. to Silliman's Journal by S. J. Brush. 



Platinum in Canada. This metal was detected last summer, in the 

 gold washings of the Riviere du Loup, where it is found sparingly 



