CHAP TEE XVII. 



ECONOMIC GEOLOGY. 



As I have already mentioned in the introduction to this Memoir, 

 j t the earlier notices of the Shan States were 



confined to vague reports of the abundance 

 of mineral wealth supposed to exist there. More or less precise 

 information was forthcoming with respect to two occurrences only, 

 the Ruby mines of Mogok and the silver-lead mines of Bawdwin. 

 Of the first of these we have an account by an eye-witness, Pere 

 Guiseppe d'Amato, written at some time before the year 1833, in 

 which he gives a, description of the methods of working the alluvial 

 deposits in which the gems are found, agreeing in every respect 

 with that given by Mr. Barrington Brown, when he visited the 

 place at least 54 years later. The Bawdwin mines were never 

 visited by a European till the beginning of the present century, 

 some 50 years after they had been abandoned by the Chinese 

 miners, who are said to have worked them for several hundred years. 

 The other minerals which are stated in the older accounts to be 

 extremely prolific in the Lao territory, as the Shan States were then 

 called, are iron, copper, lead, tin, and antimony ; but with the 

 exception of lead ore, none of these has been found as yet to be 

 sufficiently abundant to warrant exploitation by modern methods 

 of extraction. 



All the more important minerals to be found in the Northern 

 Shan States, and their mode of occurrence, have already been des- 

 cribed in papers published at various time* in the Records of the 

 Geological Survey, and it will therefore be necessary to give only a 

 brief notice of them here. 



Antimony. 



Some very pure specimens of stibnite were brought to me 

 Nam Hsan while T was in the neighbourhood of Nam 



Hsan (E 1), the capital of the Tawng Peng 

 State, said to come from the hills near the town. The prevail- 

 ing rock in that part of the country is granite, and the specimens 

 had evidently been broken from narrow veins in this rock, but 



