202 E. S. Dana—Samarshite of Mitchell County, N. C. 



mon ; and in some cases the exposed exterior of the pure min- 

 eral has taken a chocolate-brown color. 



As has been stated, indistinct crystals and crystalline masses 

 are not uncommon, and some few specimens, especially those 

 placed in my hands by Mr. Ralston, admitted of exact determi- 

 nation. The general habit, and the more common of the occur- 

 ring planes are shown in figure 1, the additional planes of figure 

 2 are rather r 



The characteristic feature of all the crystals, almost without 

 exception, is the nearly right-angled edge between the macro- 

 domes, hi. Not infrequently the elongation of this terminal 

 edge gives the crystals a prismatic appearance in that direction. 

 More generally, however, the crystals are elongated vertically 

 in the direction of the prism as taken in the figures ; a radiated 

 arrangement in the groupings of the crystals, sometimes ob- 

 served, is a feature deserving mention. The prismatic planes 

 (/and 1-2') are in all cases narrow so that the general habit is 

 that of a rectangular prism ; frequently the crystals are flattened 

 in the direction of the brachypinacoid i-t, and upon the surface 

 of this plane are sometimes observed a number of small outlined 

 crystals similar to those often occurring on the diametral planes 

 of columbite. Occasionally, also, i-i is the more prominent, giv- 

 ing rise to forms flattened in this direction. 



The occurring planes, as seen in the figures, are as follows : 

 i-I, i-l, /, i-% l-1, 1, 3- f. The planes are without luster and often 

 quite rough, so that approximate measurements alone were 

 possible ; and in different crystals some of these angles varied 

 considerably. The angles obtained from the best formed crys- 

 tals are as follows : 



= 95°; \-l^ l-t = 93°. 



the following axial ratios are < 



From these measun 



c' (vert.) 0-949, l (macr.) 1-833, a (brach.) I'OOO. 

 Some of the calculated angles for the other forms are as f( 

 lows, the angles obtained by measurement being given 

 parentheses : 



