CARNALUT 497 



In some of the recently opened mines a mixture of sylvin, 

 kieserit and rock salt is formed, known as Hartsalz. This mix- 

 ture contains almost the same percentage of potash as kainit. 5 



423. Carnallit. This mineral is a mixture of even molecules 

 of potassium and magnesium chlorids crystallized with six mole- 

 cules of water. It is represented by the symbols KCl.MgCl 2 .6H 2 O. 

 As it comes from the mines it contains small quantities of potas- 

 sium and magnesium sulfates and small quantities of other acci- 

 dental impurities. Existing, as it does, in 'immense quantities in 

 strata averaging more than 85 feet in thickness, it has been ex- 

 tensively used for the manufacture of the commercial potassium 

 chlorid (muriate of potash). As mined its color varies through 

 white, red, yellow and gray. In the strong light of the electric 

 lamp the brilliancy of carnallit crystals and their varied colorings 

 produce a strikingly beautiful effect in the galleries of the mines. 

 For many purposes in agriculture, for instance, fertilizing to- 

 bacco fields, it is not suited, and it is less widely used as a fer- 

 tilizer in general than its alteration product, kainit. Its direct 

 use as a fertilizer, however, is rapidly increasing since later ex- 

 perience has shown that chlorin compounds are capable of a far 

 wider application in agriculture without danger of injury than was 

 formerly supposed. As it comes from the mines, the Stassfurt 

 carnallit has the following composition : 



Per cent. 



Potassium chlorid 15.5 



Magnesium chlorid 21.5 



Magnesium sulfate 12. 1 



Sodium chlorid 22.4 



Calcium sulfate 1 -o 



Water 26.1 



Undetermined 0.5 



Pure carnallit would have the following composition: 



Per cent. 



Chlorin 3 8 -3 



Potassium 14-0 



Magnesium 8.7 



Water 39- 



5 German Kali Works, The Slassfurt Industry, 1902 : 12. 



6 Maercker.Die Kalidiingung, 2nd Edition, 1893 : 7. 



