98 



THE BINGEEA DIAMOND MELD. 



average specific gravity, taken from a large number, is 3'25. As 

 this is nearly tlie same as that of the diamond, we can readily 

 understand their being found together. Many must be lost in 

 the washing processes. They are oval in form, smooth, and 

 rarely exceed a quarter-inch in length. The miners can give no 

 origin for the name, and it does not appear to be mentioned in 

 any works on mineralogy, &c. 



8. BrooTcite : — Small flat fragments, very rare. 



9. Titaniferous iron :^E.ather common. 



10. Magnetic iron ore, in small grains, showing an octohedral 

 form under the microscope, coated with hidrated sesquioxide of 

 iron, easily removed by the magnet. G-old in small particles was 

 often found attached to the grains of magnetite. 



11. Wood tin : — Rare, in small rolled particles. 



12. Gold : — Pine grains and scales, present but in small quanti- 

 ty, and the greater portion attached to the magnetite ; hence the 

 magnet was found the most ready means of removing it. 



13. Osmiridium : — In small brittle plates ; rare. 



14. The Diamond : — As already stated, they are for the most 

 part small in size. Some are clear, colourless, and transparent, 

 while others have a pale straw-yellow tint. One or two dark ones, 

 very small, have been seen ; also a greenish one. The sp. gr., as 

 deduced from nineteen specimens, is 3'42 (the Mudgee being 

 3-44). 



In some the crystalline form is weU and distinctly shown, but 

 others possess very much rounded faces. Some of the best crystals 

 were those of the triakis-octohedron, the triakis-tetrahedron, the 

 octohedron, the tetrakis-hexahedron (or four-faced cube), and the 

 hexakis-octohedron. 



No fractured specimens have been detected, but it is rather 

 common to find them with very much pitted surfaces, and with 

 internal black specks. 



One of the Companies, when prospecting the ground, found the 

 drift to yield as follows : — 



6 loads yielded 



4i 



6 



6 



6 



6 



Eefuse from machines, &c. 



41 diamonds 

 143 



125 

 163 



89 

 41 



34^ 



690 diamonds. 



or an average of 20 diamonds per ton of stufi", regarding the load 

 as equal to one ton. The above were obtained by the Gw^dir 

 Diamond Mining Company. 



