Page:Transactions of the Geological Society, 1st series, vol. 1.djvu/183

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The relative age of the different formations of silver, according to Werner, is not yet determined. The vein which was formerly worked at Huel Mexico in Cornwall, was in grauwacke slate. The ore appeared to be mixed in it in the form of insulated masses or nests; besides the native silver, corneous ore (muriate of silver) was also met with. This last ore, of all the combinations of silver, is that which is most frequently found at the surface of veins.

Silver united with lead in the state of galena is found in the mine of Huel Pool, and filiform native silver, with vitreous silver and decomposed galena, has been met with at Herland; we know that these two metals combine very readily, so much so, that we rarely find a mine of lead which does not contain more or less silver. The mines of Beer-alston in Devonshire, contain a pretty large proportion of it. The most important mineral deposit at Freyberg is of silver and lead.

Grey antimony ore (sulphuret) is sometimes found in primitive, and sometimes in secondary mountains. According to most geologists it belongs to the middle ages of our globe. It was formerly; worked in different parts of Cornwall; among others at Padstow Harbour and Camelford near St. Tenth, and more lately at Huel