Pen field and Ford — Calaverite. 



233 



t, are the same as those already recorded. In the striated zone 

 a distinct reflection was obtained from a face corresponding to 

 the ortho-pinacoid a (100), which has been observed only on 

 this crystal. 



The measured and calculated angles are as follows : 







Measured. 



Calculated. 



Times 

 observed 





Symbols. 



Vertical. 



Horizontal. 



Vertical. Horizontal. 



m 



110 



00° 00' 



31°17' 



00° 00' 31°30j' 



2 



q 



11-29-5 



33 41 



15 10 



32 52 15 30^ 



1 







13-22-10 



46 50 



27 45 



47 30| 28 18 



2 



p 



111 



55 8 



46 54 



54 48 46 54£ 



2 



s 



11-62-6 



143 15 



8 13 



142 4 7 50 



1 



T 



31-38-11 



153 16 



28 55 



153 8 29 14 



1 



a 



100 



00 00 



90 5 



00 00 90 00 • 



2 



F 



11-0-5 



31 41 



90 00 



32 52 " 



1 



G 



13-0-10 



47 3 



a 



47 30£ " 



1 



1ST 



201 



144 22 



a 



144 28 " 



2 



B, 



11-0-1 



173 10 



a 



172 37 " 



1 



Although the discrepancy between the measured and calcu- 

 lated values is considerable in some cases, the agreement is 

 sufficiently close to indicate that the forms are identical with 

 those of the first occurrence. A 

 similar irregularity of contour is 

 also noticeable, as shown by the 

 figure. 



Occurrence No. 3. Crystals 

 from the Moon Anchor Mine. — 

 Our study is confined to two 

 small crystals detached from a 

 gangue specimen sent us by Mr. 

 Rickard. The crystals are lath- 

 shaped, measuring l*5 mm in 

 length and 2 by 0*3 mm in cross 

 section. The development of 

 the crystals is represented by 

 figures 18 and 19. The gangue 

 upon which the crystals occur 

 seems to be a decomposed ande- 

 site, the calaverite having been deposited along with quartz 

 and fluorite in a crevice. The forms together with their 

 measured and calculated angles are recorded in the following 

 table : 



