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of one or more species of plagioclase felspar, with a large proportion 

 of the particular mineral under notice. The minerals mentioned 

 are accompanied by much serpentinous matter and by kaolin ; 

 both due to causes affecting the rock since its exposure at the 

 surface. Other minerals associated are, as my colleague Mr. 

 Rudler has informed me, Hornblende in considerable quantity; 

 one or more undetermined species of the Pyroxenic group, Biotite, 

 and Apatite. Quartz is also found occasionally. The mineral 

 usually referred to Hypersthene is generally of a very dark bronze 

 colour on the unweathered parts, and it exhibits well-marked 

 cleavage-faces, which are silky, or sub-metallic in lustre, and often 

 of much the same appearance as the alloy known as pinchbeck. 



Some say that the mineral that has been called Hypersthene 

 at Carrick should by right have been named Diallage ; but the 

 question seems never to have been definitely settled as yet ; 

 perhaps because the mineral itself, on account of its very great 

 geological antiquity (it is certainly of pre-carboniferous age), has 

 undergone such changes as render its correct identification a 

 matter of difficulty. 



Owing to the fact that the felspar matrix of the Carrick Fell 

 rock weathers away faster than its associated minerals, large 

 crystals, frequently of an inch or more in length, of the mineral 

 now under notice, are left projecting as rough crystals with a 

 tea-green exterior on the exposed portion of the rock. It may be 

 collected in almost any quantity from the fallen rock-matter 

 accumulated on the eastern- and the south-eastern slopes of 

 Carrick Fell. 



There is at present some doubt also in regard to whether the 

 next species, Enstatite, occurs as a constituent of the rocks of 

 Cumberland and Westmorland or not. There is every reason to 

 expect to meet with it as one of the constituents of our crystalline 

 rocks. 



AuGiTE, a mineral allied in composition to the two last-mentioned, 

 but crystallizing in forms belonging to the Monoclinic, instead of 

 to the Rhombic system, occurs as an important constituent in 

 many of the eruptive (i.e. plutonic and volcanic) rocks of Cumber- 



