Mineralogy of Sky. 101 



The following varieties are the most remarkable of those which 

 are to be seen in this tract. 



1, Pure white marble, the fracture intermediate between the granu- 



lar and small platy. 



2. The same with a scarcely discernible shade of gray. 



S. The same with variously disposed veins of grey and black, re- 

 sembling the common veined marble used in architectural or- 

 naments. 



4. The same with narrower veins well defined, and often reticu- 



lated with a great semblance of regularity : very ornamental. 



5. The same, distinguished, independently of the veins, by a parallel 



and regular alternation of layers of pure white and grayish 

 white. 



6. White marble variously mottled and veined with gray, yellow, 



purple, and light green. This is also a very ornamental 

 variety. 



7. Marble, exhibiting various mixtures of white, pink, purple, 



light green, dark green, and black, of a rich sombre effect, 

 and highly ornamental. 



8. White marble, beautifully mottled and veined by yellow trans- 



parent serpentine. 



The ornamental coloured marbles here described, scarcely yield 

 in beauty to many of the similarly constituted specimens of ancient 

 marbles, and like many of the marbles of Scotland they will be 

 found to owe their colours to serpentine. This is also the case in 

 Glen Tilt, at Balahulish, and in lona. But the most obviously 

 valuable variety is the white, which seems to possess most of the 

 qualities requisite for the purposes of statuary. 



Few substances in the catalogue of those with which economi- 

 cal mineralogy is concerned have excited more interest than statuary 



