256 



C. Pal ache — Mineralogical Notes. 



ing about 2 mm in length and 05 mra diameter, being doubly 

 terminated, while the smaller ones show but a single termina- 

 tion. Except for a coarse striation on the brachypinacoid due 

 to oscillatory combination of that form with a prism, the crys- 

 tal faces are plane and brilliant and despite small size give 

 excellent measurements. 



The following forms were observed : 



c (001), b (010), a (100), m (110), I (130), / (012), g (011), 

 d (021), y (103), p (111), o (236), r (233), * s (263), t (136), 



U (1-9-12). 



In the prism zone the forms b and I are 

 dominant, often giving a slightly tabular 

 habit to the prisms. They are striated and 

 less brilliant than the narrow faces of m, 

 which are always present The pinacoicl a, 

 present on all but one crystal, gave rather 

 poor reflections. Of the terminal forms 

 the brachydome g and the unit pyramid 

 jp are dominant ; the base c, while always 

 present, is broad on but one crystal. The 

 domes f and y and pyramids o and r, 

 while found on several crystals as tiny 

 facets, are quite subordinate to the fore- 

 going forms, and the three forms d, t and 

 u were each seen but once on the same 

 crystal. 



6 7 



m a m 



The observed combinations are as follows : 



1. c, b, a, m, I, f, g, p, s. Doubly terminated. Figure 4 

 (drawn by J. B. Marvin, Jr.). 



2. c, b, m, I, g, p, s. Commonest type on specimen as a whole. 

 Figure 5. 



3. e, b, a, m, I, f, g, y, p, o, r, s. Two measured crystals. 

 Figure 6. 



4. c, b, a, m, I, f, g, d, y, p, o, r, s, t, u. Figure 7, drawn 

 in a,bout the natural develojnnent. 



