(jrolclschmiclt and Nicol — New Forms of Sperrylite. 457 



Crystal 

 No. 



1 



Measured. 



P 



46° 46 67° 50 



Calculated. 



P 



45° 00 70° 31 



4 



43° 30 



44° 37 



68° 39 

 70° 03 



45° 00 

 45° 00 



« 



5 



135° 32 



135° 35 



27° 17 



28° 32 



69° 58 

 67° 57 

 48° 06 

 48° 31 



135° 00 



135° 00 



26° 34 



26° 34 



u 

 a 



48° 11 



a 



46° 29 70° 23 45° 00 70° 31 



The faces are very small, but their frequent occurrence gives 

 them some importance. 



^ =+■££- (214), a form important for pyrite, occurs on crystal 

 ISTo. 4 with three faces, and on crystal ~No. 5 with two faces. 

 The faces are very small but possess brilliant lustre. 

 Position : 



Crystal 

 No. 



4 



Measured. 



(p p 



117° 02 79° 45 



65° 19 78° 16 



167° 16 66° 10 



Calculated. 



<p p 



116° 34 77° 23 



63° 26 " 

 165° 58 64° 07 



5 



75° J 8 

 152° 52 



65° 05 

 29° 00 



75° 58 

 153° 26 



29° 12 



x = — f-J- (213) observed on crystal ~No. 4 with one well bor- 

 dered face giving a good signal reflection. Position : 



measured : 4>p = 147° 05 ; 74° 57 

 calculated : <£p = 146° 19 ; 74° 30 



The agreement is satisfactory. The form may be considered 

 as established. 



?z = +-f-J- (315) observed on crystal 'No. 5 with one triangular 

 face. Position : 



measured : 



<p P = 48° 50 ; 79° 27 



calculated : 



cp P =z49° 02 ; 80° 16 



Owing to this agreement the form is a probable one, but 

 confirmation is to be desired. Till that is obtained the form is 

 indicated by a (?). 



?D=-f iHr (326) observed on crystal No. 7 with one face. 

 Measurement and calculation do not agree very well. The 

 form needs confirmation. Position : 



measured : cpp = 159° 10 ; 64° 39 

 calculated : <f>p= 161° 34 ; 64° 37 



