BY W. F. PETTERD, C.M.Z.S. 9 



striated parallel to their intersection with m (100). The 

 predominant forms are c (001), a (100), and m (110); the 

 others are very narrow. Two faces of a (102) admitted of 

 measurement; but the pyramids and the dome o (Oil) 

 were determined from single faces." Then follow the 

 measurements. 



" Clear, colourless, tabular crystals up to 2 inches in 

 length and J-inch in depth occur at the Susannite Mine, 

 between Zeehan and the Comstock, in the oxidised portion 

 of a lode carrying a large proportion of pyrit-e." (L. K. 

 Ward.) 



15. Ankerite ( Carbonate of Calcium, Iron, and 



Magnesium). 



This is a brown dolomite, differing from that mineral 

 in containing a considerable proportion of iron. It occurs 

 at the Heazlewood Silver-lead Mine, at the Comet Mine, 

 at Dundas, and at the Magnet Mine, at all of which local- 

 ities it forms no inconsiderable portion of the lode gangue. 

 It weathers to a dark-coloured gossan at the outcrop of 

 the lodes. At the Magnet Mine it is not unusual to find 

 the ankerite and associated veinstone minerals much 

 stained an apple-green by chromic acid, and the same 

 applies in a lesser degree to the Heazlewood. 



16. Anmabergtte f" Arsenate of Nickel). 



A secondary substance, of a bright apple-green colour 

 when pure. It is soft and commonly incrusting. It was 

 -detected in small quantity at the silver-lead mine at the 

 Penguin, and is fairly plentiful, as thin coatings on nic- 

 colite, at a locality about 2 miles from Leslie Junction, 

 Dundas. 



17. Antimony, Native. 



Occurs in thin radiating patches, about an inch in 

 diameter, implanted on a silicious matrix. A slab about a 

 foot square was obtained practically covered with this 

 •element in the form indicated. 



Locality : Spray Section, British-Zeehan Mine, Zeehan. 



18. Anorthoclase (Poly silicate of Sodium, Potassium, 



and A lu m inium) . 

 A triclinic potash felspar, whose primary form is an 

 oblique rhombic prism. It is of a shining white colour 

 It occurs in the solvsbergites of Port Cygnet. 



