Moses — Mineraloyical Notes. 



105 



The measured angles are sufficiently close to determine the 

 forms, but are injured by the many dull faces and the difficulty 

 of maintaining the rather heavy crystal and attached quartz in 

 position. 



The crystal was one of a cluster of three or four, as frag- 

 ments of two others are visible as well as their cavities in the 

 quartz gangue. The gangue also contains oligoclase, and 

 attached to the sides of the cavities in the quartz are fragments 

 of pyrite as if this mineral had filtered in between the chryso- 

 beryl crystals and the quartz. 



The crystal is shown in figure 5, the white portions shown 

 in the faces a representing very nearly as in the actual crystal 

 the deep grooves which yielded the signals corresponding to 

 m (110). 



(7) A Pyroxene Crystal from the Copper Mines of Ducktown, 



Tenn. 



Pyroxene crystals are recorded as occurring at the Ducktown 

 Mines, but I have found no description of their faces, and for 

 this reason and also for certain peculiarities I have thought 

 this crystal worthy of description. 



Among the specimens in the Egleston Mineralogical Museum 

 is a rather large brown crystal of varnish-like luster and marked 

 translucency. It measures in the directions of the axes a, 1>, 6 

 approximately 25x35x65 mm . The gangue includes a wedge- 

 shaped fragment of chalcopyrite 5 mm thick and 45 n,m long 

 attached to the vertical faces and a small amount of zoisite and 

 fibrous mineral apparently amphibole. 



The peculiarity of the crystal is, that while the prismatic 

 portion belongs to a single individual with faces a (100), h (010), 

 m (110) and f (310), the terminal faces indicate three indi- 

 viduals with a progressive change in faces, as shown in ortho- 

 graphic projection in figure 6, in which one face, u' (HI), is 

 common to all three, showing only partially the lines of junc- 



