ROCKS AND MINERALS OF CEYLON. 



43 



The third outcrops under the Great Western on the Great 

 Western estate, and is continuous to the N.N.W. with the 

 Wattegoda and Medakumbura dolomites, and probably also 

 with the beds at Gampola and Kurunegala. A subsidiary bed— 

 or it may be an outlier of this— occurs near the Pussellawa 

 rest-house. 



The fourth bed outcrops largely at Wilson's Bungalow, 

 Glen Devon, Dumbara, and Matale, 



The fifth occurs in the Badulla district. As in the gneiss 

 we have a great many varieties, so also in the dolomites. They 

 all contain carbonate of magnesia, which varies from 1 to over 

 40 per cent. 



These limestones are very valuable for estate purposes aa 

 well as for building stone and building lime. 



In colour they vary much, dependent on the numerous 

 accidental minerals that occur along with them. Thus the 

 specimens from Wilson's Bungalow are very dark : they contain 

 pyrites, phlogopite, chlorite, epidote, &c. 



A dolomite occurring at Wariapola on the Matale railway 

 contains a large amount of blue spinel. Some of the crystals 

 of these dolomites have large facets, others small and of a 

 granular texture. Many contain white translucent siliceous 

 grains not easily distinguished. 



A beautiful example of limestone of a somewhat peculiar 

 tinge, due to the metal chromium, occurs beyond Balangoda, and 

 often contains fine specimens of crystalline biotite — a magnesian 

 imica. This limestone shews a very peculiar and character- 

 stic weathered surface. 



Plumbago is found in several localities, as at Kurunegala, 

 Kegalla and Nambapana. In the Balangoda district we have 

 the metal Molybdenium, so useful in chemical researches ; and 

 black oxide of Manganese from Ratnapura and neighbourhood. 



Various forms of iron occur in the gneiss, thus iron pyrites, 



