106 



Mercury should not occur where it was said to have been found ; 

 but hitherto no ore of Mercury has been detected within the limits 

 of the British Isles ; and then again, one has heard so often of 

 such things being dropped by accident or otherwise in places 

 much frequented by people interested in mining matters, that until 

 the existence of the ore in situ has been actually demonstrated to 

 the satisfaction of mineralogists. Cinnabar cannot be included in 

 the list of minerals occurring in Cumberland and Westmorland. 



The case is far different with the next mineral on the list — 

 Blende, Black Jack, or Zinc Sulphide. This is one of the most 

 widely-distributed ores, and at the same time one of the most 

 easily-recognised of the minerals occurring in our district. It is 

 found principally, perhaps exclusively, in fault-fissures, or in the 

 adjoining rock ; generally in association with the lead-veins and 

 the copper-veins occurring throughout the two Counties. 



Blende is sometimes mistaken for Cassiterite, or Tin Oxide ; but 

 Blende may be known at once by yielding to the knife more easily 

 than the ore of tin does, as well as by its presenting a much more 

 even fracture. Blende crystallises in the Cubic System, and its 

 crystals are in great request among spar-hunters on account of their 

 beautiful lustre. Beautiful examples of Blende, coated with pearly 

 crystals of Dolomite, from Keswick, and others from the Alston 

 district, adorn the National Collection; while other equally-fine 

 specimens from our district may usually be found in most collections 

 of minerals. 991 tons, 8 cwt. of Zinc, having a money value of 

 ;^36i2 IS. od. were raised from the Cumberland mines in 1880; 

 but part of this may have been obtained from the Zinc Carbonate, 

 or Calamine. 



Great quantities of Blende will remain unutilised in the dead- 

 heaps of our mines until Metallurgists shall teach us some 

 more economical method of reducing this ore to the metallic 

 form. 



Traces of Cadmium Sulphide usually occur in association with 

 Blende in the same way as Argentite is associated with Galena, 

 and Gold with Chalcopyrites ; but its actual existence in the 



