Mr. William Phillips on the Veins of Cornwall, 117 



Denominations of Metalliferous Veins, 



The substances which form the contents of the metalliferous' 

 veins differ very materially ; nor are veins distinguished simply by 

 the name of the ore for which they are wrought, as a Copper Load, 

 or a Tin Load ; but they have obtained various appellations, ac- 

 cording to the nature of the substances found to predominate in 

 them. For as the greater proportion of the contents of most of 

 them, is neither the ore of copper nor that of tin, the miner in 

 speaking of them, gives them the appellation which is technically de- 

 scriptive of the vein-stones : — as a gossany, sparry, mundicky, peachy, 

 flucany, scovan, caply, pryany, black jack, and a grouany Load. 



Gossan is a friable ferruginous substance, consisting generally of 

 clay, or of some siliceous matter of a loose texture, coated or tinged 

 with iron, in various proportions, arising probably from the decom- 

 position of pyrites ; it varies in colour, from pale yellow to deep 

 red, sometimes inclining to black. A Gossany Lode is more com- 

 mon than any other, and most promising both for tin and copper. 

 Gossan has been plentifully found at small depths in many mines 

 that produced considerable quantities of one or the other metals, 

 both beneath as well as mingled with it ; as of tin in Huel Sparnon 

 and Pednandrae, and of copper in Huel Gorland, and in East and 

 West Huel Virgin. 



When the load or contents of a vein is termed sparry^ this does 

 not im.ply that it is of solid spar or quartz, but that quartz predomi- 

 nates. A vein in which this substance is considerably compact is 

 very unpromising ; and if at the same time the vein becomes nar- 

 rower as it descends, it is generally relinquished as a hopeless under- 

 taking; which was the case in Huel Gorland, as noticed in my memoir 

 on the red oxide of copper.* A vein abounding in fluate of lime 



* Geological Transactions, toI. 1, 



