114 



Galena, Chalcopyrites, Fluor, Calcite, and Barytes in both 

 localities. 



III. 



The Third Division comprises the compounds of the Metals 

 with the Halogen elements — Iodine, Bromine, Chlorine, and 

 Fluorine. Of these only the two following species are represented 

 here. 



One of the best-known and most widely distributed minerals 

 occurring in our district is Fluorite, Fluor spar, or Calcium 

 Fluoride. As a rule Fluor spar occurs chiefly in the lead veins 

 traversing the Carboniferous rocks, and it does not occur in any great 

 quantities in the non-calcareous rocks, even where the other minerals 

 that usually accompany it are found in tolerable abundance. In 

 the lead-mining districts it occurs perhaps in nearly all the veins of 

 one part, while in the veins of an adjoining area, traversing precisely 

 the same rocks, and, to all appearance, produced under precisely 

 similar conditions, it is frequently conspicuous by its absence. Its 

 vertical distribution also seems to be equally irregular ; and the 

 vein-stuff that in one part of a lode contains this mineral in 

 abundance may be totally devoid of it a hundred feet or so lower 

 down. Like the Galena it is so frequently associated with, Fluor 

 does not often occur, perhaps it hardly ever occurs, except in the 

 rock in connection with a fault. Our Fluor usually occurs in the 

 form of cubes, and its colour varies so much that, beyond the 

 statement that its commonest tint is that of the amethyst, no 

 general description can be given. In the mines around Cross 

 Fell beautiful examples of the dichroic variety of Fluor spar 

 occur. These appear of different colours, according as they are 

 viewed by reflected or by transmitted light. The most beautiful 

 specimens of Fluor obtained in Cumberland generally come from 

 the mines of the Alston district, which has furnished examples of 

 this species to nearly all the leading collections in the kingdom. 



Halite, Common Salt,or Sodium Chloride, may justly be claimed 

 as a Cumberland and Westmorland mineral for more than one 



