30 MINERALOGY AND LITHOLOGY. 



with a hammer, or in the partially pulverized mineral. It has been pre- 

 dicted that, at some future time, these deposits can be profitably worked. 

 Some specimens of zinc blende from New Hampshire have been an- 

 alyzed by Dr. Jackson, who obtained the following results : 



The blende from Madison was yellow, while, owing to the amount of 

 iron present, the others were all nearly black. All the analyses, save the 

 one of the blende from Warren, correspond very nearly with the correct 

 formula (Zn, Fe) S. In the analysis of the Warren blende, the amount 

 of sulphur is too small, and this indicates some alteration of the mineral. 

 The uniform presence of cadmium is very noticeable ; and the Lyman 

 and Shelburne blendes would be considered as very rich in this metal. 

 The blende in New Hampshire is not often found in good crystals, but 

 in its massive condition it usually shows on fractured faces the charac- 

 teristic dodecahedral cleavage. 



14. ClIALCOCITE [Cuj, S]. 



This sulphide of copper is not common. At some places it accompa- 

 nies other copper minerals, though in small quantities. At Oxford it 

 occurs associated with the green carbonate of copper and with copper 

 pyrites. It is not in crystals, but in noncrystalline masses and grains, 

 recognizable by their dark gray color on a fresh fracture, and by the 

 malleable copper globule, which is obtained by heating the mineral on a 

 piece of charcoal with the blow-pipe. 



15. Pyrriiotite [Fct, Sg]. 



This mineral is found in some places in veins forming large deposits, 

 and it is also scattered all over the state as a constituent of the rocks. It 

 has not been found in crystalline form, but it occurs in bronze colored 

 masses, associated with other kinds of pyrites, from which it is distin- 



