Mineralogical Journey. 



301 



length, thirteen twentieths of an inch in breadth and four tenths of 

 an inch in thickness. When viewed by transmitted light, it reminds 

 one of the finest Syrian garnet j but seen by reflected light, it 



red, peculiar to the oriental rub v. Its 



crimson 



freedom from cracks, united to its transparency, luster and beauty of 

 color, have caused it to be much admired by jewellers.* 



Among the smaller crystals which pencti^ate the crystallized quartz^ 

 a few are perfectly colorless and transparent- Their form is that of the 

 Tourmaline nonO'sepiimale, H.j and from their exquisite finish, they 

 are well fitted for goniometrical examination. The following figure 

 and accompanying measurements are intended for their illustration. 



Inclination of 



Ponk 

 Ponl 

 k on I 

 I on I 



s on s 



Reflec. Goniometer 152^ 40' 



. . 117 13 



a 



(( 



a 



u 



u 



u 



u 



C( 



90 

 120 



120 



A few crystals of transparent Indicolite, of a deep color, were met 

 with, which were associated with Rubellite, and imbedded in Lepido- 

 lite. From one of these, I had two tables (five eigdis of an inch by 

 half an inch) cut and mounted j but, although of a good color, then' 

 beauty is injured by several cracks. Fragments of a less transparent 

 variety of Indicolite were pretty abundant; also small, somewhat flat- 

 tened crystals of Rubellite, with one or two polished faces, and pos- 

 sessed of a good color and considerable transparency; and a few 

 transparent prisms of the green Tourmaline, precisely resembling the 

 same mineral from Brazil. 



1 had formerly observed, that fragments of the above described 

 Tourmalines became electric, on being held to the fire for a few mo- 

 ments; but it was not until very recently, that 1 discovered the ex- 

 treme sensibility of my polished specimens to electrical excitement. 

 Having placed the Rubellite broach for a few moments near some 



* These Tourmalines were cut and polished by Messrs. Mod tanye & Mason, Lapi- 

 tiaries, 93 Reed street. New York. Another crystal, which I have in the hands of 

 a lapidary in London, I am informed, has afforded a red broach, which is regarded as 

 ''a great curiosity." 



