358 THE GEOLOGIST. 



veins abounds with this looseness and inaccuracy, I take the present 

 opportunity of giving a few definitions on the subject, which I shall 

 continue as occasion may require. 



Definitions kelating to Veins and Metallifeeous Deposits. 



I. English miners commonly say that such and such a rock con- 

 tains no mineral, meaning thereby that it contains no metallic 

 mineral, or mineral of the useful metals. As all rocks consist of 

 minerals, of course such an expression is incorrect. In speaking of 

 the minerals of the useful metals they should be described as metallic 

 minerals or ores. 



II. As all rocks consist of minerals, it is evident, when the ex- 

 pression mineral-vein is applied exclusively to those veins containing 

 ores, that such limitation is also incorrect. Mineral-veins are uni- 

 versal in every formation, but ore -veins only are generally valuable 

 to man. Rock-veins also occur. The following are definitions of 

 these three classes of veins : — 



Rock-Yeins are fissures filled up with such mineral aggregates as 

 also occur in large masses as rocks ; as for example, granite, elvan, 

 greenstone, or sandstone. 



Mineeal-Veins, on the other hand, are fissures filled up with 

 minerals, or combinations of minerals, such as do not occur as rocJvS ; 

 as for example, crystallized fluor-spar, baryte, quartz, &c. 



Oeb-Yeins are either mineral-veins or rock-veins, in which ores are 

 always present. 



III. From these definitions it appears that ores may occur in rock- 

 veins as well as mineral- veins. They may also occur in roch-masses 

 which are not veins, but may be heds, or stocks, which latter is the 

 German word for an ore- containing rock-mass that is neither a vein 

 nor a bed. Stocks are divided into 



Standing-Stocks, irregular ore-containing rock-masses with some- 

 thing vein-hke in their character ; 



Lying- Stocks, the same, with something of a bed-like character. 



Beds are accumulations of ore, or of rock-masses containing ore, 

 lying parallel to the stratification in stratified rocks. 



IV. The expressions mineral-veins and metalliferous deposits are 



