362 Geological Survey of the Island of Jersey. 



completely, from the action of a few years' sun and rain, (for 

 there is but little frost in Jersey). This effect has been pro- 

 duced in a striking manner at i, on the north side of the St. 

 John's road (see 24 and 25) in less than six years. Thin 

 seams of black oxide of manganese, in great abundance, per- 

 vade the interstices between the planes of stratification. 



Water is plentiful and excellent during summer and winter. 



Felspar Rocks. 

 Under this head may be arranged felspar alone. 

 I j A very compact and intensely hard sort of a pink- 

 ' \ g re y colour, passing into 



Another, equally hard, of a blue-green cast, but con- 

 36. } taining crystals of pale-buff felspar in abundance, 

 forming a decided and beautiful porphyry. 



26. f A dark bluish green (externally, but dark grass green 



27. -J when cut and polished) porphyry, with the crystallized 



28. ( particles of a spicular form. 



, f A light yellow ochre-coloured variety of No. 1, but 



' I more decidedly porphyritic. 

 10. An irregularly laminated and pink-red porphyry. 



Ditto, containing concretions, sometimes nearly sphe- 

 rical (like those in the pisolite), in concentric coats, and 

 internally radiated, at other times irregular : a curious 

 rock. 



3. A fine grained variety of 10. 

 5. A white variety of 2. 



Felspar and Quartz. 

 43. A fine granular species. 



Felspar and Hornblende (Greenstone). 



]5 39 \ 



'I Greenish-white felspar and hornblende in various 



I9I4Y. J ProP 01 ^™ 8 - 

 16 and 17. Felspar and Schorl. 



13, 41, 42, 45, 52. Felspar, Quartz, and Hornblende (Fel- 

 spar, red). 



2. 



4. 



12. 



