256 



JOURNAL, R.A.S. (CEYLON). 



[Vol. IX. 



under that head. I have never seen anything approaching to real 

 anthracite in the Island. 



"I return the samples. The specimen of pyrites (iron), quartz 

 r ock, and plumbago is exceedingly interesting." 



Mr. Murray wrote again with reference to some other 

 specimens I sent for his inspection 



" The minerals you got at De Mel's are all iron pyrites closely 

 associated with plumbago. The ferruginous appearances of some 

 of the specimens I am inclined to attribute to oxidation through 

 the agency of water or damp rinding its way along natural fissures* 



" The specimen of plumbago is perfect, and exhibits an exceed- 

 ingly fine form of crystallization. 



" Still more interesting is the specimen of garnetiferous quartz 

 associated with plumbago. The dark dullish mineral in the quartz 

 matrix is, I believe, an amorphous form of plumbago in a state of 

 transition, for, on breaking a piece off your specimen for the purpose 

 of testing it, I found secretions in a semi-carbonised state which 

 were easily pulverised. 



" The crystal (octahedron) of iron pyrites is certainly exquisite, 

 and one of the forms by which it is recognized. 



" Among other forms of crystallization the cube is common. I 

 enclose some crystals of it, which please return after inspection. 

 They were taken out of the gneiss quarry at Fishers' Hill, 

 Mutwal." 



Rocks associated ivitk Plumbago. 

 Having received from Mr. Williams, Acting Government 

 Agent of Kurunegala, a very fine mass of quartz crystal found 

 in a plumbago mine, and which bore traces of having been embed- 

 ded in kaolin, I obtained Mr. Murray's opinion of the specimen, 

 thus : — 



" The specimen of translucent rock crystal is exceedingly 

 fine. The crystal is the typical form — rhombohedral — a six-sided 

 prism terminating in a six-sided pyramid ; the white earthy 

 substance is kaolin. 



" Crystals in process of formation assume plane, smooth surfaces : 

 the polished facets are not due to the influence or action of other 

 closely -associated minerals, but are merely the definite shapes or 

 forms assumed in obedience to the laws of crystallization. Geo- 

 logically, quartz belongs to the metamorphic or hypogenic system, 

 and contains one equivalent of silica to two of oxygen.'' 



On other specimens of pyrites, mica, quartz, &c, found associ- 

 ated with plumbago, Mr. Murray reported thus : — ■ 



