276 RECORDS OF THE AUSTRALIAN MUSEUM. 



The observed combinations are shown in the following table 

 (ii. is the figured crystal). 



From the means of a large number of excellent measurements 

 yielded by the forms m and o the following axial ratio was 

 calculated :— a : b : c - -52894 : 1 : -47754. 



GYPSUM. 



Mount Elliott Mine, Chillagoe District, Queensland. 



(Plate lxxix., fig. 3.) 



At this mine vei*y fine examples of crystallised selenite are 

 found in association with native copper; I am told that prismatic 

 crystals ten feet in length have been obtained. The crystal 

 figured measures 2 x 1-5 x 20 <-m.; it is terminated by the fibrous 

 fracture parallel to t (101) and twinned on a (100). The forms 

 were determined by measurement with a contact goniometer, the 

 approximate angles obtained being : — 



6(010)A5(350) = 41°; calc. 41° 22'. 

 6 (010) A™ (110) -55°; calc. 55° 44'. 



ANGLESITE. 



Proprietary Mine, Broken Hill, N. S. Wales. 

 (Plate lxxx., fig. 1.) 



Some brilliant colourless crystals of about 3 mm. diameter, 

 associated with crystallised iodyrite and marshite, were observed 

 on a limonitous matrix from this mine. Two crystals were 

 measured and found to be anglesite of a type quite different from 

 previously described Broken Hill anglesite. 1 The most prominent 



faces belong to a(100), o (01 1), y (122) ; »i (110) and a inter- 



• 



4 Toborffy— Ann. Mus. Nat. Hung., v.. H)07, pp.494-496, pl.xi., figs. 1-6; 

 Id. — Zeits. Kryst., xliv., 190S, pp. 601-()03, pi. xi., figs. 1-6; Anderson — 

 Austr. Mus. Rec, vii., 1908, pp. 63-65, pi. xiv. 



