MINERALOGY, 49 



The molybdite of Westmoreland contains six tenths of one per cent, 

 of oxide of uranium,*" which makes the mineral from this locality remark- 

 able, and which gives to it a deeper yellow color than is common in spec- 

 imens of molybdite. 



37. Quartz [Si O2]. 



This mineral, which forms the larger part of the crust of the earth, 

 is of particular importance in those parts of it that are occupied by 

 old crystalline rocks like New Hampshire. 



Common transparent, glassy quartz forms a large proportion of our 

 rocks, and is, moreover, found in the most grand and beautiful crystalli- 

 zations. On Moose mountain some very fine and large crystal masses 

 have been found. A group of these crystals in the Dartmouth College 

 cabinet weighs 147^ pounds. It contains forty-eight crystals, four of 

 which are from five to five and a half inches in diameter. Fine, large, 

 clear crystals are also found at Benton, Littleton, Bartlett, Hanover, War- 

 ren, Westmoreland, the White Mountain Notch, and Raymond. 



The crystals in some localities have a smoky tint. Smoky quartz is 

 found at Bartlett, Cornish, and the Notch. The Cornish specimens are 

 penetrated with rutile ; and the presence of titanic acid is supposed by 

 some to impart the smoky color to this variety of quartz. 



Quartz of a delicate rose color, called rose quartz, occurs in mica 

 schist rocks in the White Mountains, at Acworth, Raymond, Andover 

 (on Ragged mountain), and Keene. It is quite abundant on Mt. Wash- 

 ington ; and much of it is annually carried away by tourists. 



Amethyst or purple quartz is found at Surry, Mt. Crawford, Waterville, 

 and Westmoreland, — at the latter place in fine crystals. Moreover, some 

 fine, large crystals have been ploughed out of the soil in Amherst. Some 

 of these were three inches in diameter and eight inches long. Fine, 

 rolled pieces are found at Hampton Falls. Quartz with a purplish tint 

 is common. 



Among other occurrences of note may be mentioned beautiful green 

 crystals, colored by epidote, at Franconia and Enfield ; fine red and yel- 

 low crystals, colored by oxide of iron, at Francestown, Gilmanton, and 



* Jackson. Geology of Neiv Hajnpshire, p. 230. 

 VOL. IV. 7 



