SOME NEW YORK MINERALS AND THEIR LOCALITIES. 



L-MWCOMB TOURMALINES. 



There are many specimens in the collection which, for various 

 reasons, demand more than casual mention. Among these may be 

 noted, material from a newly discovered locality at Newcomb, Essex 

 county, N. Y. This locality has yielded some of the finest specimens 

 of brown tourmaline yet found. The exact position of the bed is on 

 the south shore of Lake Harris about one mile east of the post-office 

 in Newcomb. These tourmalines occur in the Laurentian limestones 

 which are so abundant in the valleys of the Adirondacks. The same 

 limestones occurring in the northern part of New Jersey, in Orange 

 county and in northern New York, all bear more or less brown tourma- 

 line. The most famous locality, however, is Gouverneur, N. Y. For 

 the most part, the tourmalines occurring in other places are very frag- 

 mentary, presenting the appearance of having been nearly dissolved 

 after being formed. It is not of infrequent occurrence that crystals are 

 found having only one or two of the R-faces present with traces of 

 the prism, or that a fine termination is present with a diameter of 

 one to three cm. with the c. axis no more than five mm. in length. 

 In other cases mere crystalline shells appear, or fine veins may be 

 completely filled with the formless mass. In general the mineral is 

 only feebly transparent and more usually opaque. Even when in 

 large, finely developed crystals the contrary is a rare exception. In 

 many cases, however, the opacity of the crystal is due to numerous 

 fine shivers passing in every direction, and there is a decided cloudi- 

 ness which renders the crystalline masses opaque. Many of the 

 larger crystals have a single termination at one extremity, while 

 the other will have from two to twelve distinct terminations, and 

 should the inclosing calcite be dissolved away for a short distance, 

 they would give the impression of as many distinct crystals having 



