1 84 



NEW YORK STATE MUSEUM 



been frequently recorded for pyrite. The development of the zone 

 [210. 001] is specially characteristic of this crystal, the forms occur- 

 ring as follows : (210), (421), (211), (212), (213), (214), (001). 



The forms occurring in the zone [001. no] are: (001), (112), 

 (in), (221), (no). 



The forms were identified by means of their zonal positions as 

 follows : 



LETTER 



ANGLE 



NO. 



MEASURED 



CALCULATED 



1 



Zone [100 



no] 





: e 



: 



100 : 520 

 : 210 

 : 650 



2 

 II 



8 



21° 39' 



26 35 

 39 44 



21° 48' 

 26 34 



39 48 







Zone [210 . 



001] 





c : t 



: n 



•P 



: s 

 :t" 



210 : 421 

 : 211 

 : 212 

 : 213 

 : 214 



8 



13 



10 



6 



6 



12 36^ 

 24 3 

 41 47 

 ^2> 19 

 60 48^ 



12 36 

 24 6 

 41 49 



53 18 

 60 48 







Zone [100 . 



III] 





"■ : n 

 ■P 



100 : 211 

 : 122 



6 

 5 



35 16 

 15 46I 



35 16 

 15 47? 



The specimens loaned by the New York Mineralogical Club were 

 collected several years ago by Dr George F. Kunz. The two loose 

 crystals selected for study measured about 10 mm in diameter and 

 VN-ere rather more distorted than the smaller crystal from the Man- 

 chester collection. These proved to be of a distinctly different type 

 from either the Manchester crystal or those described by Moses. A 

 crystal of this type is shown in figure 3 and an enlarged portion of 

 the octahedral field in (figure 4.) Although for the most part the 



planes are well developed and brilliant, 

 they show a greater tendency toward the 

 formation of vicinal planes, particularly 

 in the zone [100. iii|. On one of the 

 two crystals measured this tendency finds 

 expression in the production of a vicinal 

 prominence of the octahedral face. In 

 addition to the forms noted by Moses 

 the following were observed: 72(211), 

 Fg.4 ^'^(311), /H322), m(522) and n(755). 



