ON SOME NEW SOUTH WALES AND OTHER MINERALS. 23T 



In some of the massive specimens of haematite there are distinct 

 veins and strings of ordinary quartz ; such masses when acted 

 upon by hydrochloric acid leave a more or less cellular or porous, 

 non-gelatinous residue of quartz not unlike certain varieties of 

 geyserite or siliceous sinter deposited by hot springs, but the 

 specific gravity is 2*55, and the hardness 7 and no combined 

 water seems to be present, hence the mineral possesses the pro- 

 perties of ordinary quartz rather than those of sinter. Some of 

 the quartz looks as if it had originally been charged with iron 

 pyrites which has since been converted into oxide of iron, (such 

 a mixture when occurring at the outcrop of a lode is usually 

 termed gossan); the oxide has in parts been subsequently removed 

 leaving a spongy siliceous skeleton. 



Mr. It. L. Jack, f.g.s., Government Geologist, Queensland, has 

 carefully examined and described the Mount Morgan deposit and 

 attributes it to geysir action, but the specimens examined by me 

 may have come from a part having a different origin, and as I 

 have not visited the locality, I am unable to express an opinion 

 upon the main question. 



Magnetite. 



In the form of a massive, imperfect crystal, but with some of 

 the faces well marked ; possesses but slight magnetic properties. 

 Brown outside giving it the appearance of brown haematite^ 

 Weight 195-303 grammes, the sp. gr. at 18° C. was found to be 

 4 -9 3. Sfear Cowna Station, Barrier Ranges. 



Molybdenite — Molybdenum di-sulphide. 



In the form of large lamellar plates most of which show two> 

 to four edges of a hexagon. Some of the masses are nearly three 

 inches thick, and as much as 3 J inches across and 5 J inches long, 

 with extremely well marked cleavage, hence, very thin sheets, 

 with most brilliant lustre, of nearly 1 5 inches superficial area can 

 readily be obtained. 



