ORNAMENTAL STONE, 21 



(z>).=- Ornamental stone. 



A short distance east of Kasipur the sillimanite schist is traversed 

 by narrow veins of a very fine grained cryptocrystalline aluminous 

 rock, reddish or brownish in color and soft enough to be cut and carved 

 into small ornaments. It is locally much prized under the name of 

 Lai patther. (Specimen 13M83.) I think it is a fault rock formed 

 from Khondalite. 



(»*)•— Diamonds. 



In examining some sands obtained from the streams near Bondesor 

 I observed several minute crystals of a highly refracting colorless 

 mineral. These grains were examined under the microscope both by 

 Mr. Havden and myself and we came independently to the same con- 

 clusion, that they were diamonds. Though they were too small to be 

 of value they very probably indicate that others of larger size may be 

 found if carefully searched for. The sands in question must have been 

 derived from the Khondalites which as previously stated usually con- 

 tain graphite. A few years ago Professor Becke of Prague pointed 

 out that when two or more minerals crystallising differently have the 

 same chemical composition, the denser, the one with the higher 

 specific gravity, is usually found in rocks that have been subjected to 

 very great pressure. From this point of view it should be expected that 

 rocks containing carbon in the form of graphite might contain dia- 

 monds if the graphite-bearing rocks were subjected to sufficient 

 pressure. These conditions are probably present in the Khondalites 

 which may become diamondifercus instead of graphitic where the 

 pressure has been intense. 



