1 8 8 2 .] Mineralogy. 835 



Report upon the Geology and Mining Industry of Leadville, Col., 

 by S. F. Emmons, contains thorough details of the Palaeozoic 

 and eruptive Mesozoic rocks of the district, and of the ores, 

 which principally occur underneath a porphyry sheet and chiefly 

 in cavities penetrating the " Blue " limestone, the lowest member 

 of the carboniferous. 



MINERALOGY. 1 



Chrome Tourmaline. — Cossa and Arzruni describe in the 

 t Ziitschntt fur Krystallographie a new variety of tourmaline, in 

 which chromic oxide replaces a portion of the alumina. The 

 tourmaline, of a deep green color, occurs in deposits of chromic 

 iron in the Ural mountains. The crystals have a beautiful di- 

 chroism, appearing, when viewed by daylight, yellow brown, par- 

 allel to the optic axis, and blue-green at right angles to the axis. 

 Viewed by lamplight the yellow-brown color changes to ruby- 

 red, and the green color nearly disappears. The result is, that 

 the crystals are green by daylight and intense red by lamplight — 

 a phenomenon shared by alexandrite. 



The chrome tourmaline has a specific gravity of 3. 120. Before 

 the blowpipe it melts somewhat easily to a grayish-white, opaque 

 bead. With borax and salt of phosphorus it gives a fine green 

 bead, and in the latter flux a skeleton of silica. It is only de- 

 composed by acids after fusion. The analysis was as follows : 



S»0, Bo a A1 2 3 Cr 2 0. ( FeO M-0 CaO NaO H,0 F 

 3^79 9-51 30.51 10.86 2.91 4-47 -72 1.36 2.25 .65 = 100.08 

 > of Ram- 



, Paraffixp: in Lava.— O. Silvestri has found that the basaltic la 

 m the n ighborhood of Etna, contains small geodes filled with sol 

 cry.st.-illized paraffine. The paraffme is in large translucent plat 

 °f waxy appearance and yellowish-white color, with a meltii 

 point of 56 . It is soluble in ether and in boiling alcohol. 



New Localities. — A. Schmidt describes small transpare 

 crystals of newbervite from Mejellones, Chili. They occur 

 crevices in guano, and having bright lustrous faces, could be a 

 Cl »-ately measured in the reflecting goniometer. They are orth 

 rhombic in tabular crystals, with a hardness somewhat more th: 

 3. and a specific gravity of about 2.10. Newberyite had pr 



Damour gives an from the Urals, and Ar 



