On the Geological Distribution of Gold. 33 



the property of a few proprietors. In the year 1827 there 

 were discovered two or three quartz veins, producing gold, 

 traversing the granite, and found below the fluvial detritus. 

 I shortly after went to see these discoveries, and found that 

 among them only one quartz vein was worked with good 

 profit. That no connexion between the gold from these 

 veins and that gathered from the fluvial detritus can be 

 found, will be explained by the following comparison of the 

 gold got from the different positions. 



Gold from the veinstone in the Granite below the auriferous 

 fluvials. — The appearance being fungiform, irregular and with 

 rough outlines, the particles of a few grains weight, of a pale 

 yellow colour, veins No. 1 and No. 2 presenting the same 

 appearance. 



Assay of No. 1 gold 70-84 silver 29-16 



Do. No. 2 „ 68-76 „ 31-24 



Gold from the Fluvial detritus resting on the Granite above 

 the Veins. — The appearance being lamellar, thin particles of a 

 rounded outline, quite smooth and of clean surface, the largest 

 particles about tire size of a linseed, and partly very small 

 flat grains, of which the number of 60 were required for 

 the weight of one grain, the colour being a deep yellow. 

 When seen with the microscope the larger grains had a deeper 

 yellow shade round the exterior outline. From one of the 

 localities a few slender particles of platinum were observed, 

 this being the only locality within the boundary of Antioquia 

 where platinum has been found. 



Assay from locahty No. 1 gold 83-00 silver 17-00 



Do. No. 2 „ 88-21 „ 11-79 



The highest quality of gold in South America is found 



among the fluvial productions, where to the north of the 



equator, in Pamplona, it gives 98-95 gold and 10 - 05 silver, 



being a very fine lamellar dust. 



In California the fluvial gold has also produced the highest 

 quality, showing but a small fraction below that just named 

 from South America. 



In Australia the highest quality or purest gold is also 

 found among the fluvial detritus, from whence also the largest 

 mass of this metal has been taken from a locality, at the 

 depth of 160 feet, the gold resting on micaceous clay slate. 

 The shape of this curiosity presented two distinct masses bound 

 together by a flattened piece of gold, about 1 and 1| inch 

 in dimensions, but the smaller portion covered the larger ex- 



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