MINERALOGY. 29 



higher, and others much lower than this. Galena from Monroe, Conn., 

 yielded Mr. P. Collier 874 ounces of silver to the ton. Thus these ores 

 vary much in their value, and, though widely distributed, it may be quite 

 safely affirmed that New England will never add any very great amount 

 to the world's production of silver. 



12. BORNITE [Cu3, Fe, S3]. 



This sulphide of copper occurs sparingly associated with other copper 

 ores in this state. At Jackson it is found associated with the copper py- 

 rites and the tin oxide. Large specimens of it are obtained from a metal- 

 lic vein in Dalton ; and at Shelburne it is associated with copper and 

 zinc ores. At Littleton it is found in what is called the White Mountain 

 mine, associated with chalcopyrite. It has not been found in crystals, 

 but is generally in a massive condition, mixed with the yellow copper, 

 pyrites, from which it is easily distinguished by its color, which, on a 

 fresh fracture, is between copper-red and brown ; but, where it has been 

 exposed, it is always tarnished to a purple color, on account of which it 

 is called purple copper, or variegated copper ore. 



13. Sphalerite [Zn, S]. 



There are some large deposits of sphalerite or zinc blende in New 

 Hampshire, although thus far they have not proved themselves to be of 

 economic value. At Warren there is a large vein of black blende. 

 Blende, when pure zinc sulphide, is nearly colorless, but it usually con- 

 tains some iron, which replaces a portion of the zinc, and the black color 

 of this blende at Warren results from the presence of much iron. There 

 is also a deposit of this black variety of blende in Shelburne, and another 

 in Lyman, while at Madison there is a large vein of a much lighter col- 

 ored blende, which, as might be supposed, contains very much less iron, 

 Haverhill, Rumney, Monroe, and Croydon are other localities of note ; 

 and this is a mineral that one is constantly meeting in small quantities, 

 in veins and crevices of the rocks, recognizable by its resinous lustre, 

 though this property, usually so characteristic, is not easily seen in the 

 black ferruginous varieties that are so common with us. In them, this 

 resinous appearance is best seen on the spot, where a piece is struck 



