MINERALOGICAL NOTES : No. VI.— TOPAZ, BERYL, 

 ANGLESITE, RUTILE, ATACAMITE, PYRITE. 



By C. Anderson, M.A., B.Sc, Mineralogist 

 (Plates xiii.-xvi.). 



TOPAZ 



Cow Flat, near Torrington, New Sooth Wales 



(Plate xiii., figs. 1, 2.) 



Two specimens from this locality were examined and measured. 

 Fig. 1 represents a crystal from the collection of the Department 

 of Mines ; it occurs in situ in a small vugh, accompanied by 

 crystallised quartz and three smaller topaz crystals, at Fielder's 

 Hill. The habit is stout prismatic, the dimensions 12x 12x 12 

 mm., and the colour pale blue. For measurement the entire 

 specimen was mounted on the two-circle goniometer with the 

 face rri" (110) polar, the forms being determined from the stereo- 

 graphic projection by aid of Penfield's protractors. The base is 

 quite rough; /and y slightly inter-oscillate. 



(Ss/The other specimen (Plate xiii., fig. 2) consists of an isolated, 

 transparent, colourless crystal of 2-7 x 2-2 x 16 cm. The basal 

 plane and the dome /are roughened by oscillation with y and h. 

 The prism faces are as usual striated vertically, and some of them 

 yield multiple images ; n (140) is doubtfully present. 



*' The measured and calculated co-ordinate angles are tabulated 

 below; Dana's ratios and lettering are used throughout. 



