144 The MonocUnic Pyroxenes of New York State. 



Pj^roxene. Garnet. 



MgO 5.23 10..50 



FeA 4.70 17.08 



ALA 8.44 5.05 



MnO .70 



Alkalies 50 



Loss on Ignition 20 



99.33 



Blum (Ref. 3) has described the alteration of pja'oxene to mica 

 in the augites from Monroe Township, Orange county. The 

 sides of the crystals are almost entirely covered with brown mica 

 (clintonite), which is the same color as the augite. The mica, 

 plates have their cleavages in approximately parallel position. In 

 one crj^stal only a core of the augite remained. 



Detailed Account op Pyroxene Localities. 

 Augites. 

 For convenience the occurrences are divided into the Adiron- 

 dack Area and the Highland Region, under each of which heads 

 the localities are arranged alphabetically. 



I. The Adirondack Area. 



Adams Lake. — The writer feels some hesitation in describing 

 this locality under the heading of New York State, for while 

 there are a number of specimens in the Columbia University col- 

 lection which are labeled "Adams Lake, N. Y.," there is also a. 

 crystal exactly like the others labeled "Adams Lake, Can.," and 

 I am informed by Prof. F. D. Adams that there is a Canadian 

 locality of this name, which is a baj- of Lake Rideau, in lots 2, 3, 

 4 and 5, Ranges Y and YI, N. Burgess township, Ontario. 



The crystals are light green and 1|^ inches long, with smooth 

 faces which are bright in places, but also show some uralite. 

 They are all doubh?^ terminated. The combination of forms- 

 present in all is a (100), 6(010), m(llO), uQll), s(Ill),o (221),. 

 c (001) and p (lOl). (PL XYI, Fig. 7.) The dome z (021) may 

 occur. Both basal and orthopinacoidal partings are present. 



Bonaparte Lake, Leivis Co. — There is one crystal in the collec- 

 tion of Columbia University which is said to come from this 

 locality. It is exactly like those described from Adams Lake. 



Cascadeville, Essex Go. — Granular pyroxene in a calcite vein 

 is found on the mountain side above Long Pond, opposite the 



