Ladon 



Kil 



Pass. 



Chotok. 



30-10 



27*36 



450 



4-02 



312 



3-78 



1-20 



1-50 



•74 



•27 



2-06 



2-86 



1902.] D. Hooper — Occurrence of Melanterite in Baluchistan. 237 



as Ehaghal forms. This is of a yellow colour and is said to be in an 

 excellent condition for dyeing purposes. 



Upon examining the samples of Khaghal it was soon discovered that 

 they were impure forms of ferrous sulphate or green copperas. The 

 sample from Ladon Pass contained 30" 1 per cent., of anhydrous ferrous 

 sulphate, and that from Kil Chotok 27 '36 per cent. Analyses of the 

 water-soluble portions of the minerals revealed the fact that in addi- 

 tion to the iron salt sulphates were | present of other available metals 

 peculiar to the rock. The following tables indicate the composition : — 



FeS0 4 



A1 2 3S0 4 



CaS0 4 



MgS0 4 



K 2 S0 4 



Na 2 S0 4 



41-72 39-79 



The minerals contained about 40 per cent, of matter insoluble in 

 water consisting of silica, iron, alumina and lime. These estimations 

 leave a balance of about 20 per cent, which might be referred to water 

 of crystallisation. 



The specimen of Khaghal from Bhapar yielded to hot water only 

 a small quantity of sulphate of alumina with traces of calcium sulphate, 

 and was therefore almost valueless as a dye or mordant. 



Melanterite or native ferrous sulphate is usually the product of the 

 decomposition of pyrites and occurs as an efflorescence on the out-crop 

 of rocks containing a considerable quantity of this mineral. But in 

 volcanic regions it appears to be formed by the chemical action of sul- 

 phurous vapours upon siliceous and oxidised ores of iron. There are 

 volcanic regions in Baluchistan where sulphur is obtainable and where 

 sulphurous fumes are constantly acting upon the surrounding rocks con- 

 verting the metals into sulphates. The Khaghal mines of Nargana 

 and Chotok provide the conditions of warmth, air, and moisture neces- 

 sary to promote the combination of sulphurous acid and iron and the 

 ultimate conversion into crystallised sulphate. 



Iron sulphate has already been found in India in the following 

 places : Shekawati, Rajputana ; 1 hills of the Kakur district, Afghanis- 



1 J. C. Brooke, J. As. Soc. Beng,, Vol, xxxiii,, 529. 



