Vein Quartz, under four conditions. 



(i) Constituting the whole thickness of a Lode or Vein, 

 in which case the latter may be said to be a Quartz Vein, 

 unless the quartz contains much valuable ore, such as Lead 

 or Copper, for then it will more frequently be called a Lead 

 or Copper Vein with a quartz vein-stone. Some of these 

 Quartz Veins are of considerable width — many yards — and 

 run in straight lines, sometimes for several miles, though 

 often broken by faults. That they contain gold in small 

 quantities is certain, and I have in my possession some small 

 grains of this precious metal extracted from a vein of Quartz in 

 Borrowdale. It is well known that gold has been mined in Wales 

 for a great many centuries, but it seems not to exist in any of our 

 Cumberland Quartz Veins in workable quantities, so far as I have 

 been able to judge. 



(2.) Instead of being itself a lode or vein, quartz h-equently 

 forms strings or courses running in or through a lode formed of 

 various mineral substances. Supposing the lode be lead-bearing, 

 it often becomes an important question, how much of the vein-stone 

 be quartz, and how much calc-spar, baiytes, or other minerals. 

 For the quartz is very much harder than most other constituents ot 

 veins, and if the ore has to be extracted entirely from such a matrix, 

 the labour is much increased. Nevertheless, sometimes even a 

 quartz ore vein-stuff is quite crumbling, and when so, the working 

 is comparatively easy. This is the case with several lead-veins 

 occurring in the Vale of Newlands. 



(3.) Quartz when occurring either as a massive lode or a 

 slender string is opaque, and generally of a pure white colour ; but 

 it occurs, thirdly, in the form of clear transparent crystals, lining 

 the sides of cracks and fissures either in massive quartz or in some 

 other mineral substance. These crystals have the general form of 

 a six-sided prism terminated by a six-sided pyramid ; but owing to 

 variations in the relative size of the several faces the appearance of 

 the crystals may vary. Sometimes also they are coloured in various 

 tints, due to oxides of iron, manganese, etc., mingled with the 

 oxide of silicon, or silica, as it is more usually called. It will be 



