175 



CONTRIBUTIONS TOWARDS A LIST 



OF THE MINERALS OCCURRING IN CUMBERLAND 



AND WESTMORLAND. (Concluding Part.) 



By J. G. GOODCHILD, F.G.S., F.Z.S., H.M. Geol. Survey. 



(Read at the Penrith Annual Meeting.) 



Following the arrangement adopted in the parts of the List 

 already published, the section of minerals that next comes under 

 notice begins with the important group of rock-constituents known 

 as the Silicates. These are primarily grouped in two series — the 

 Anhydrous, and the Hydrous Silicates. Each of these again is 

 subdivided in accordance with the ratio between the Oxygen and 

 the base combined with it. These subdivisions are further classed 

 according to their respective crystallographic characters. 



Taking the group wherein the ratio of the Silica to the base is 

 as 2:1, and the crystallization is in forms belonging to the Rhombic 

 system, the first mineral we have to refer to is Hypersthene 

 (MgO, FeO) SiOz. The existence of this particular species any- 

 where within the district herein specially referred to has been 

 much questioned of late by competent authorities. The principal 

 locality where it is considered by many persons to occur, is at 

 Carrick Fell, where, if it has been correctly identified, it forms an 

 important constituent of the beautiful rock composing a large part 

 of that mountain. This rock, all are agreed, is rock of igneous 

 origin — many regard it as a highly-metamorphosed series of old 

 lava flows — and it now consists of a coarsely-crystalline aggregation 



