526 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 59. 



The indices are improbable and are not confirmed by the zonal 

 relations or by the position of the form in the normal series, as shown 

 below. This must consequently be considered a disturbed and 

 abnormal form. 



fc x (794) occurs as a small face on crystal 41, as shown in figure 18. 

 The face, in addition to being small, was somewhat etched. The 

 angles are: 



(794) Measured ^ = 50° 11' p = 77° 12' 

 Calculated cp = 50° 46' p= 77° 29' 



A = 0° 35' A = 0° 17' 



This form also fails to fit in the normal series for its zone and is 

 therefore a disturbed and abnormal form. 



\ (9.16.2) occurred on crystal 10 as a narrow rounded face between 

 o (120) and r (231), as shown in figure 19. The angles measured are: 



(9.16.2) Measured <p = 41° 25' p = 85°47' 



Calculated *> = 41° 33' p = 85° 46' 



A= 0° 08' A = 0° 01' 



The rounded face gave a band of signals. The measurement was 

 made on a brighter and more pronounced signal in the center of the 

 band. The form is poorly confirmed and is somewhat doubtful. 



m x (12.25.1), a form with such high indices that it may almost be 

 considered vicinal to o (120) was observed as 7 distinct faces on 5 

 of the crystals examined. It is consequently believed to be a well- 

 substantiated form. Of the crystals measured, Nos. 33 and B9 

 yielded the following angles: 



(12.25.1) Measured, XL 33 p = 37° 11' p = 88° 33' 



Measured, B9 ^ = 36° 40' p = 88° 14' 



Measured, B9 ^ = 36° 44' p = 88° 18' 



Measured, average <p = 36° 52' p = 88° 22' 



Calculated </> = 37° 07' p = 88° 27' 



A= 0° 15' A- 0° 05' 



This form occurs as a narrow line sometimes completely etched, 



beveling the edge between o (120) and m* (011). 



