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by their own decomposition, some oi the constituents that have 

 entered into fresh combinations with the products of decomposition 

 arising from the action of percolating waters upon the contents of 

 the mineral veins. Another factor to be taken into account is the 

 great length of exposure of the fell-tops here, as compared with 

 other parts adjoining. This, of itself, must have led to great 

 complexity in the contents of the mineral veins, as there must 

 have been ample time under such circumstances for many minerals 

 that had crystallized as decomposition-products in the lower parts 

 of a vein to be again and again dissolved and afterwards recombined, 

 often under different circumstances, with mineral matter of a totally 

 different kind. The decomposition of the various sulphides, of 

 phosphates like Apatite, of Wolfram, of Mispickel, as well as of 

 the varied assortment of silicates associated with the veins of the 

 Caldbeck Fell area has had a very important influence in bringing 

 about great variety in the mineral constituents of the waters perco- 

 lating down from the surface, as successively lower portions of the 

 veins were exposed by denudation. 



Caledonite is another rare mineral found in the same two 

 mines; though it has been found more often at Red Gill than 

 at Rowtin Gill. It occurs in the form of small crystals of a bluish- 

 green colour, ranging between turquoise-blue to what is known 

 as peacock-green. These are found shooting inwards towards the 

 centres of the cavities in the quartz-rider. 



Leadhillite is yet another of the rare mineral species found at 

 the same localities as the last, and often found associated with it, 

 and Linarite, Cerussite, Anglesite, etc., in the same specimen. 

 Usually it occurs in the form of small tabular crystals, cleavable 

 with great facility in one particular direction, and otherwise bearing 

 a close resemblance to white mica. It is usually brilliantly-lustrous, 

 and is clear and colourless. Crystals over an inch across have 

 occasionally been met with at Red Gill ; but it is usually in smaller 

 crystals than that. 



Hydrous Arsenates. 



Ervthrine, Erythrite, Cobalt-Bloom, Cobalt Ochre, the Hydrous 

 Cobalt Arsenate, is found at Force Crag Mine, near Keswick, at 



