45 



Gypsum. 



As a rock. — As another of the rocks of the district, the gypsum 

 group holds an important position from the large area it occupies. 

 Closely associated with the gypsum itself are certain thick zones of 

 greenish, sometimes smoothly stratified, clay, often containing translu- 

 cent crystalline plates or fragments of selenite which glisten on its 

 weathered slopes ; these clays have only been found to enclose impressions 

 of small fragments of grass-like plants. 



Occurring with the clays, and in places as if below the main 

 gypsum, or both below and above it, are bands of limestone sometimes 

 hard and compact, sometimes flaggy and transversely crossed by a' 

 fibrous crystalline structure, which more or less perfectly takes the well- 

 known form of ' cone-in-eone/* 



Both the gypsum and associated clay have received from the natives 

 distinguishing names, the gypsum being as well known by the name 

 SpeenJci as the salt by that of Malga (Pushtu), and the clays being called 

 SheenJcoura. 



Character and solubility \ — The gypsum, as indicated by its Pushtu 

 name, is very generally of a white color, showing itself plainly even on 

 dark days at long distances among the hills, but it sometimes has a 

 grayish hue,f more rarely variegated with deep red from decomposition 

 of iron, and it often in its lower part passes into shaly beds, quite black, 

 smelling strongly of petroleum ; its texture varies from subcompact to 

 more crvstalline varieties. 



* Close outside the district. 



f The Potwar gypsum is also white or gray, and associated with clays very similar to 

 Slieenlcoura. 



( U9 ) 



