154 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



profitable mining of the Indian deposits still more impossible. Since in India no new and 

 rich deposits have been discovered to take the place of the old, worked-out mines, as has 

 been the case in Brazil, the time cannot be far distant when India must be excluded from 

 the list of diamond-producing countries. 



It has been thought that the diamond-mining industry of India might revive were 

 mining operations to be in the hands of Europeans instead of in those of the natives. 

 Several attempts have been made in this direction, but up to the present have been attended 

 with but little success. The mines most suited for experiments of this kind are those 

 situated in districts directly under English control, namely the Chennur mines in the Penner 

 valley, and those of Karnul and Nandial, Sambalpur, and Chutia Nagpur. Though the 

 economic, social, and legislative conditions even here are none too favourable for the under- 

 taking and carrying out of systematic work, they are less adverse than in districts under the 

 sway of native rulers, such, for example, as those in which the Golconda and the Panna 

 groups of mines are situated, and which are very inaccessible to Europeans. As the 

 geological structure of the country is worked out and becomes better known, it is possible 

 that new occurrences of the diamantiferous beds may be discovered, though it must be said 

 that at present there is no immediate prospect of such discoveries. 



The insignificance of the annual output of Indian diamond-mines has already been 

 commented upon ; the proportion of these stones which reaches the European markets is 

 still more insignificant ; indeed, it is doubtful whether any appreciable number leave the 

 country at all. This state of affairs finds its parallel in the times preceding the eleventh 

 century ; now, just as then, the stones are kept in the country to satisfy the passion for 

 gems of the great Indian princes and magnates. Another inducement to dealers to keep 

 the stones in the country is the fact that they will frequently make a higher price there 

 than in the European markets, where they must undergo comparison with the treasures of 

 the whole world and where the price is regulated by the inexorable laws of supply and 

 demand. So brisk is the demand for diamonds in the Indian markets that the native 

 supply is barely sufficient, and many foreign stones are imported, especially from the Cape. 



There are not many detailed statements of the mineralogical characters of Indian 

 diamonds ; a few, however, have been collected and are given below. 



It is often stated that the usual crystalline form of Indian diamonds is that of the 

 octahedron, while that of Brazilian crystals is more often the rhombic dodecahedron, the 

 two being often distinguished as the Indian and Brazilian types respectively. This view, 

 however, is not in complete agreement with some recent scientific investigations of stones 

 which are certainly known to have been found in India. It appears on the contrary that 

 the octahedral form is seldom seen in India, the more characteristic forms being the 

 tetrakis-hexahedron and the hexakis-octahedron. Of fourteen crystals of diamond in the 

 Museum of the Geological Survey of India at Calcutta, which were examined by Mr. F. 11. 

 Mallet, nine show a tetrakis-hexahedron alone, two show this form with subordinate faces of 

 the octahedron, two are octahedra in combination with a tetrakis-hexahedron, and one is an 

 octahedron in combination with the rhombic dodecahedron. A tetrakis-hexahedral form is 

 thus present in thirteen of these fourteen crystals, and on eleven of them it occurs singly or 

 predominates over other forms ; on the x)ther hand, the octahedron is present on five crystals 

 only, and on only three of these does it predominate. Of the fourteen crystals examined, 

 five were from the Karnul district (four tetrakis-hexahedra and one octahedron with tetrakis- 

 hexahedron), one from Sambalpur (tetrakis-hexahedron with octahedron), four from Panna 

 (much distorted tetrakis-hexahedra), the remaining four being, said to have come from Simla. 

 Also of thirty-one Indian diamonds in the mineralogical collection at Dresden only six are 



