224 J. MILNE CURRAN, 
*The consensus of so many practical men, taken with the high 
specific gravity I find so notable in Bingara diamonds, should I 
think allow us to conclude that, the Bingara diamond is really 
harder, than the diamonds usually found at the Cape or in Brazil. 
I have learned the following facts about Bingara diamonds, and 
as I found the information much needed, I may be permitted to — 
introduce it here. A first-class stone from Bingara when cut 
weighed slightly under one carat. It sold readily in London for 
£14 10s. 5d. A Bingara stone with a tinge of green weighed 
when cut $ and 4; carat, and sold readily for £10. Four parcels 
of Bingara stones were sold by one gentlemen, who informs me 
that the average was four to a carat. It was always difficult to 
dispose of them, and the figure realised ranged from 4/6 to 8/- 
per carat on the average. The following extract! may be of 
importance to many. In valuing the diamond one must attend 
‘firstly, to the size of the stone and proportionate shape for 
cutting ; secondly, as to whether they be white and free from 
defect. Rough diamonds are calculated half their weight, as 
they are supposed to lose 50% in cutting and polishing. The price 
of doing this may be estimated at from 12/- to 15/- per carat.” 
Auburn Vale.—The diamonds found here under precisely the 
same conditions as at Bingara. The country rock is granite, but 
the diamond-bearing drifts and their relations to the basalt and 
the associated minerals are the same. 
Mittagong.—Southey’s Diamond Mine is situated seven miles 
south-east from Mittagong. The gems are found here in a drift 
associated with other gem-stones. The drift is not unlike the 
Auburn Vale deposits, but the absence of tourmaline is at once 
_ apparent, The volcanic-breccia that seems to underlie the drift 
here, and to which attention has been called by Messrs. Wilkinson 
and Wood, is thought by many to be the matrix of the diamond. 
This has to be confirmed. The drift is surrounded by Hawkes- 
PRs 
1 Diamond Mining in South Africa by William Hanbly Esq.—Trans- 
actions of the Mining Association of Cornwall, Vol. 111., pt. i., pp- 17, 18 
