Mineralogical Journey. 



299 



of the other,) a perfect line of demarkation caii be traced- From 



these observations, I am led to infer, tlint the brown Quartz was first 

 deposited from sohition, and surrounded the walls of the granitic 

 cavity with its crystals; and that the Tourmalines crystallized next, 

 to which succeeded the Talc and Felspar; and that, finally, the white 

 Quartz was deposited around the other substances- And we observe, 

 consistently with what is noticed concerning crystallizing fluids in our 

 laboratories, that the last portions of such fluids afford crystals possess- 

 ing less perfectly the attributes of crystallization, — the white Quartz is 

 much inferior in transparency and delicacy of fracture to the smoky 

 variety. 



The large, loose cr}^stals of Tourmahnes affect the general form of 

 trihedral prisms w^ith convex faces, which are deeply striated. They 

 resemble each other very considerably, as respects transparency, 

 fracture and color, — being as clear, for the most part, as tiie intensi- 

 ty of their colors will allow; free from flaws, except for a thin coat- 

 ing at their surfaces ; and where the crystal possesses any consider- 



green at one extremity , and red at the other. They 

 have a tendency to break across at distances of about tlie diameter of 



able length 



with 



fragments almost globular in shape, 



ro 



quite free from flaw^s, and "of the finest water." Of these crystals 

 and fragments of crystals, I shall describe a few which appear to me 

 to be tlie most interesting. 



and 



mal 



diameter equals its length. Its color Is an intense 



grass-green with a tinge of blue. It is regularly te: 

 ished faces, as represented in the annexed diagram. 



pol 



Inclination of 



P on P Common Goniometer, 133^ 30 



. 158 12 



. 158 45 



P 



on X 



oc on X 



T on t 

 t on t 

 P on t 



u 



u 



a 



u 



u 



u 



u 



cc 



157 



149 15 

 151 



; '-^L h^ 



I 



M 



t 

 I 



H' 



1 



t 



No. 2, IS a fragment, three quarters of an inch m length, by one 

 inch two tenths in diameter ; the extremities of which have been ren- 

 dered flat by the lapidary. Its colors are faint j and it exhibits the 



