[ 516 ] 



XXX. 



OK THE CRYSTALLI:NE form or EIEBECKITE.i By W. J. 

 SOLLAS, LL.D., D.Sc, E.R.S., Professor of Geology and 

 Miaeralogy in the University of Dublin. 



[Read January 28, 1895.] 

 RlEBECZITE. 



System, oblique 



a:l:c = 0-54748 : 1 : 0-29246, /3 = 76° 10'. 

 Observed forms 



^(010), c(OOl), m(llO), (^150), 



r(lll), 



i!(201), 2(021). 











Observed. 



Calculated. 



m 



: m = 



(110) (110) 



= 



56° 



— 



in 



: e = 



(110) (001) 



= 



77 50' 



— 



m 



: b = 



(110) (010) 



= 



62 



62° 



I 



: c = 



(010) (001) 



= 



89 48 



90 



Z 



: b = 



(150) (010) 



= 



20 39 



20 37' 



3 



: c = 



(021) (001) 



= 



29 32 



29 36 



s 



: b = 



(021) (010) 



= 



60 28 



60 24 



3 



: m = 



(021) (110) 



= 



65 28 



65 28i 



Z 



: r = 



(021) (111) 



= 



31 37 



31 25 



t 



c = 



(201) (001) 



= 



54 20 



— 



t 



m = 



(201) (110) 



= 



54 42 



55 1 



t 



. r = 



(201)(111) 



= 



27 54 



28 2i 



r 



m = 



(111)(110) 



= 



68 3 



68 4 



r 



b = 



(111) (010) 



= 



74 23 



74 22 



r 



c = 



(HI) (001) 



= 



34 6 



34 7 



r : 



r = 



(Til) (111) 



= 



31 14 



31 12 



^ Communicated by permission of the Director- General of the Geological 

 Survey. 



