142 



Fragments of gem-stones have been reported widely dis- 

 tributed amongst the river gravels. Notable amongst these 

 is the occurrence of diamondin in the gold-bearing gravels of 

 Ecliunga. Fifty or more saleable diamonds were got from 

 this field, some embedded in a hard cement at the base of the 

 wash, others in the softer gravels above. 



Abundance of almandine garnets,(^) locally called Aus- 

 tralian rubies, have been got from the river gravels, notably 

 from the MacDonnell Ranges. These are excellent stones 

 when cut, and would be much more in vogue were they not 

 so abundant. 



Mr. H. Y. L. Brown has reported small fragments of a 

 variety of gem-stones from the auriferous gravels at Daw's 

 Diggings, Kangaroo Island. 



They include the following : — Oriental ruby, sapphire, 

 amethyst, and white sapphire; also ryairite, zircon, and tour- 

 maline — monazite and rutile are present also. 



Sapphire and cyanite have been reported in gravels from 

 the vicinity of Mount Crawford, in the Barossa Ranges, and 

 from the Echunga field, but no exact and detailed informa- 

 tion is published. 



The gravel, from which were isolated the stones specially 

 referred to in this paper, was obtained as a refuse jDroduct 

 from puddling operations at the Gordon Reward Claim, 

 about one and a half miles south of Williamstown. The pro- 

 perty has been worked for gold and rutile. Numerous shafts 

 sunk on it show the depth to vary from nil to 30 ft. Only 

 the lower foot or two has been found profitable to work. 



The extent of this placer has been delineated by the 

 Geological Survey Deartment,^^' and it is referred to as Ter- 

 tiary in age. In general these gravels are to be correlated 

 with the late Tertiary and recent auriferous gravels of East- 

 ern Australia. 



At the Gordon Reward Claim the placer formation occu- 

 pies ten acres or less, and forms a flat capping (see plate vi., 

 figs. 1 and 2) on steeply-dipping schists. The flat top is part 

 of a once continuous base level, since then much dissected by 

 the South Para River and its tributaries. Other fragment- 

 ary relics of the high-level alluvial occur in the vicinity, and 

 are figured in the official map. 



The underlying schists are either Pre-Canibrian or part 

 of the lower Cambrian series highly metamorphosed, which 

 latter have been traced in the vicinity by Mr. W. Howchin. 



(5) Note specially, "On some So-called South Australian 

 Rubies," by Professor E. H. Reniiie, Trans. Roy. See, S.A., 

 vol. xi., p. 17. 



(6) ''Geological Map of the Tertiary Deposits of the Hundred 

 of Barossa," by H. Y. L. Brown, 1889. Published by authority. 



