no. 2376. 



CREED IT E EMM COLORADO- -FnsilAC. 



423 



* 



(111,111) 



'j / 



34 34 



34 27 



34 23 



34 13 



34 28 



A v. =34 29 



(111, 111) 



o / 



54 37 



54 37 



51 31 



54 37 



51 37 



54 3G 



(111,111) 



o / 



28 48 



28 50 



28 44 



28 49 



28 50 



28 44 



20 10 



28 50 



28 57 



.Ml, 111 



52 59 



52 51 



53 08 

 53 0(1 

 52 52 



52 41 



53 08 

 52 51 

 52 50 



Av.=28 

 //' = 1.1597 



52 57 



From these x' -0.7181, y' = 1.1597, e' = 0.0786, M = 85° W 

 /3 = 94° 30'. Since these are x' and ?/' for the unit form, //,, =0.7181, 

 </' = 1.1597. These reduce to the 

 monoclinic elements p = 0.7159, 

 q = 1.1562, 6 = 0.0785. Also 



a = 1.6199 and c = 1.1597. 



The following forms wen- ob- 

 served : 



c = (001). This face varies in 

 size from minute to large. I Fsually 

 dull and etched. 



Measured 89° 15' 



Calculated 90° 00' 



4° 42' 

 4° 30' 



a = oo (100) . Sometimes occurs 

 as a very narrow face with faint 

 but distinct signal. 



4> p 



Measured 90° 00' 90° 00' 



Calculated 90° 00' 90° 00' 



m=oo(110). This is the only 

 prism observed. It is usually bright 

 and gives sharp signals. On the 

 second type of crystals it is some- 

 what curved and gives a multiple 

 signal. 



Measured 31° 45' 90° 00' 



Calculated 31° 45' 90° 00' 



1= +20 (201). Occurs occasionally as dull faces yielding no reflec- 

 tions and measured by the position of maximum illumination. The 

 face is generally of good size. 



<t> p 



Measured 89° 00' 56° 15' 



Calculated 90° 00' 56° 25' 



Fig. 1.— Creedite crystals, Type l. 



