MINERALOGY. 33 



&CIBIFSROUS AI^AUNO-EAIITHY ZSEINEBALS* 



ALUM. 



Alum is found in a reddish slate clay, or soft clayslate 

 in the valley of the Tenasserim, about forty miles below 

 Matah at the forks; this, with an indurated sand from a 

 neighboring locality that also contains it, is the only alum 

 that has been yet met with in the Provinces. 

 Sulphate of diamine and potash. 



A LKALINO EARTHY MINERALS, 



MICA. 



Mica is found in the mica slate and granite, but has 

 ^iot been met with in large plates on this coast, though 

 such are sometimes seen for sale in the bazar. It is usu- 

 ally white, but black mica occurs in the granite of Double 

 Island. It is often by a misnomer called talc. 

 coeggn 



FELSPAR. 



Crystals of felspar abound in the granite, and where it 

 is porphyritic as on Double Island, and on the islands op- 

 posite Yay, they are sometimes quite large. It is usually 

 white, but the granite at the mouth of Tavoy river, on 

 the east side, is studded with beautiful crystals of flesh- 

 colored felspar. 



MOON-STONE. 



Some of the '• cat's eyes" that are brought for sale by 

 the Ceylonese, are made of adularia or moon-stone, a va- 

 riety of felspar found in Ceylon resembling opal. In 

 Europe it is often sold for opal. 



