Auriferous Sandstones of Chiltern. 287 



from feifuuinous stain inside. In size tiiey range from a nutmeg 

 to that of a man's head. Particles of gold are frequently visible 

 on a fresh fracture to the naked eye, for the planes of these 

 minute crystalline particles are highly polished, and reflect the 

 light well. The pebbles are of varying degrees of coarseness ; 

 they are very porous, and are seen to consist of more or less 

 rounded quartz grains with numerous small cavities between, 

 and in these cavities is a ferruginous substance, and on this the 

 particles of gold occur. 



By crushing and panning-ofi" these pebbles yield a "tail" of 

 tine gold that is heavy and "hangs well" in the spoon or dish, 

 but the particles are so microscopically fine that once they 

 become dry they float away on the surface of the water. This 

 gold is of good colour and high degree of fineness, and consists 

 of small crystals that sparkle in the light. This distinctive 

 character of the gold holds good both for the loose rounded 

 pebbles of sandstone found in the gravel, and also for that found 

 in the bed-rock below. 



Last month the writer re-visited the locality with the object 

 of arriving at some definite conclusion, and was fortunate enough 

 to tind a specimen which is the key to the whole matter. This 

 is a pebble of slate 4^^ in. long, 1^^ in. wide, and 1| in. thick, and 

 boat shaped. It was found about 400 feet lower down the lead 

 than where the Devonshire Reef is crossed. It was split into 

 two portions along a cleavage plane. One side is thickly spangled 

 with crystalline dots of gold on the cleavage plane, and the 

 cleavage plane of the other side has a few spangles of gold also. 

 A margin around the edge of the plane with the most gold on it 

 is bare of gold, showing that the pebble had the gold deposited 

 upon it after it was formed into a pebble, and while it was in 

 the gravel of the lead; and this shows that solutions containing 

 gold must have traversed the lead, and where the conditions were 

 suitable this gold was deposited in moie or less crystalline form. 

 Just as the gold was deposited in the slate pebble, so, no doubt, 

 it was also deposited in the sandstone pebbles while they were in 

 the gravel of the lead. By means of such a solution the slate rocks 

 and sandstones forming the floor of the Caledonian Lead could 

 also be impregnated with gold to a greater or lesser depth below 

 the floor of the lead. To further check the matter the soil on 



