189 



Plaster of Paris. An alloy formed of eighty per cent, of steel and 

 twenty per cent, of tungsten possesses a degree of hardness that has 

 never yet been obtained in the manufacture of steel [Bristow 

 Mineralogy, p. 410). The cost of transport, however, in the case 

 of the localities herein named, is against the remunerative employ- 

 ment of our supplies of this mineral. 



Associated with Wolfram at Brandy Gill is the Calcium Tungstate 

 ScHEELiTE. This usually occurs in the form of tetragonal pyramids, 

 more or less modified by other crystalline faces. The specimens 

 now obtainable at Brandy Gill are more or less decomposed. The 

 crystals are of the colour of Hock, and are lustrous and translucent. 

 Specimens an inch or more in length are not uncommon. Good 

 crystals are in the Museums at Carlisle, Keswick, and Penrith. 



Stoltzite, Lead Tungstate, has already been mentioned as one 

 of the rare minerals occurring at Force Crag Mine, near Keswick. 

 I have not seen the mineral from that locality ; but Mr. Bryce M. 

 Wright {op. cit.) states that it occurs in the form of minute yellowish, 

 or brownish, pyramidal crystals. 



Sulphates. 



Anhydrite occurs in connection with the hydrous Calcium 

 sulphate Gypsum at Coat Hill. Probably it will be found at other 

 localities where Gypsum occurs, when proper search is made. It 

 is usually of a somewhat bluer tint than Gypsum, and it differs 

 from that mineral sufficiently in hardness to be readily detected. 



Celestine is said to have been obtained at Burton in Westmor- 

 land, in limestone. It is certainly one of the minerals that may 

 be expected at many other localities, especially in connection with 

 the argillaceous members of the New Red Series. 



Barytes, Heavy Spar, sometimes called Cawk by the miners, 

 the Barium Sulphate, is of common occurrence throughout nearly 

 all the mineral veins of the two counties. Specially fine and 

 perfect crystals have been obtained from the mines in the neigh- 

 bourhood of Milburn and Dufton ; especially from Silveraband. 

 One such crystal, the largest single crystal of Barytes ever found,*. 

 was obtained from the last-named locality, and was exhibited in 



