MINKKALO(;iOAL NOTKS ANOKfiHON. 



121 



angle being 64°28. On y (130) are striations with = 29", ap- 

 proximately. The form O (560) is represented by lines in m ( 1 10). 



TaTB lilVKK, QUKENSLAND. 



(Plate xxxvi., tigs. 2-5.) 



For the loan of theHe and other Queensland topaz described in 

 this paper I am indebted to Mr. H. Dunstan, Government Ge- 

 ologist of Queensland. 



The topaz of the Tate River was shortly described by G. vom 

 Rath= ; he found the forms m (HO), / (120), /■(021), y (041), d 

 (201), o (221), but did not figure the crystals. The specimens 

 which I have examined are small, averaging 4 x 6 x "7 cm ; some 

 are very well formed with smooth Ijrilliant faces giving good 

 reflections ; the habit is either pyramidal (figs. 2, 3), or domal 

 (fig. 4). The terminal faces are etched progressively from the 

 apex downwards, the base when present l)eing quite dull • this 

 .seems to be a constant feature of worn topaz crystals. The form 

 V (121), present on one crystal, 1 liave not previously encountered 

 on the ninnerous Australian crystals which have passed through 

 my hands. 



Below are the average co-ordinate angles obtained from tlie 

 three measured crystals. 



"Rath— Sitz. Niedenh. Ges. Bonn, xliv., 1887, p. 291. 



