84 Dr. KiDD OA/ the Mineralogy of St. David* s* 



of it is here and there altered by the action of the weather, after the 

 manner of ferrihte. 



On the coast, a httle to the north-east of Penherry, is a slate 

 quarry ; worked out of a mass of schist, which forms remarkably 

 bold and nearly perpendicular cliffs, the strata of which are occasio- 

 nally much contorted. The surfaces of the laminse of the slate have 

 sometimes an ochry tarnish, and abound with minute particles of 

 mica. 



St. David'' s Slate Otiarry. 



This quarry is situated between St. David's Head on its north, 

 and a beach called the White Sands on its south side. The slate is 

 of nearly a black colour, and is here and there traversed by veins of 

 brownish white compact and indurated clay, containing tarnished 

 cubical crystals of iron pyrites. The slate is employed in roofing ; 

 but does not thoroughly resist the action of the weather, perhaps 

 from the effect produced on pyritical matter disseminated through 

 it : wherefore it is customary in all this part of the country to white- 

 wash the roof as well as the walls of their houses. 



The laminse of this slate are sometimes wrinkled or wavy. It 

 contains but faint traces of mica ; and sometimes approaches to the 

 character of siliceous schist. 



The White Sands. 



This name is given to a beach of about one-third of a mile in 

 length, which at its northern extremity is separated from St. David's 

 slate quarry, by a low and narrow ridge of rocks projecting into the 

 sea ; and is terminated at its southern extremity by high cliffs. 

 Towards the land it is bounded principally by heaps of sand j inter- 



