45 2 



The National Geographic Magazine 



that we imported, while during that 

 year precious stones of the value of only 

 $338,000 were found within our borders. 

 These were principally sapphires from 

 Montana, turquoises from New Mexico, 

 Arizona, Nevada, and California, and 

 tourmalines and chrysoprases from Cal- 

 ifornia. 



The United States Geological Survey 

 has just published a report by Mr George 

 F. Kunz on ' ' The Production of Pre- 

 cious Stones in 1902,"* which contains 

 much interesting information as to the 

 origin of the different stones. 



Nearly all the diamonds come from 

 the Kimberley mines. 



The South African mines have re- 

 covered from the set-back of the Boer 

 war, and apparently have an inex- 

 haustible supply of diamonds. In the 

 various mines a total of over 40,000,000 

 loads of blue or diamantiferous ground 

 is blocked out, meaning probably more 

 than 10,000,000 carats of diamonds. 

 The largest pile of diamonds ever 

 brought together was collected at the 

 De Beers mine in South Africa in July, 

 1900. The directors wanted to know 

 the quantity of diamonds necessary to 

 fill a certain measure. Diamonds of all 

 kinds were put in just as mined, and it 

 was thus ascertained that a cubic meter 

 of diamonds weighs 11,976,000 carats 

 and has an approximate value of about 

 $76,000,000. Up to the present time 

 the Kimberley mines have produced 

 more than $500,000,000 worth of uncut 

 diamonds. 



The number of diamonds from Brazil 

 has fallen considerably during the last 

 several years, because of the crude and 

 unsystematic methods of hunting for 

 them. Some 5,000 people are engaged 

 in diamond mininsr there, but their tools 



*The Production of Precious Stones in 1902. 

 By George F. Kunz. Extract from mineral 

 resources of the United States, calendar year 

 1902 : David T. Day, Chief of Division of 

 Mining and Mineral Resources. Washington : 

 Government Printing Office. 1903. 



are the commonest — a hoe, a crowbar, 

 an iron hook on the end of a pole, or a 

 hammer and two basins for washing 

 the gravel. The accompanying illustra- 

 tions show two remarkable carbons from 

 Brazil found on one claim — the first in 

 1894 and the second in 1901. The car- 

 bons are split into many pieces and used 

 for diamond drills. The present output 

 of 2,500 carats of carbons a month can- 

 not supply the demand for them for 

 mining and drilling machinery. The 

 price per carat demanded by the min- 

 ers in the field has jumped to $11 and 

 $11.20 for carbons, which is more than 

 is paid for average uncut diamonds. 



A new diamond field is being ex- 

 ploited in southwestern Borneo, where 

 diamonds have long been known to exist. 

 In the region of the Landak River, near 

 the mouth of the Soran River, a piece of 

 so-called serpentine has been obtained 

 which incloses a diamond apparently in 

 its true matrix. The Rajahs of Panem- 

 bohan and Pongerans possess an im- 

 mense belt studded with diamonds, said 

 to be from this district, one stone weigh- 

 ing 67 carats. It is a peculiar belief of 

 the natives that the gold and diamonds in 

 the earth are a sort of bank, and should 

 be worked only when they themselves 

 need money, since the}- believe that gold 

 and diamonds are always there when 

 they desire them. The great Borneo 

 diamond of Mattam, said to weigh 367 

 carats, is believed to be from this same 

 region. 



India, so long renowned in history 

 and tradition as the source of gems, 

 produced in 1902 no diamonds and no 

 precious stones, with the exception of 

 considerable numbers of rubies mined 

 in Upper Burma. The leading gem 

 dealers of Paris and Amsterdam have 

 agents at Mandalay who buy the rubies 

 directly from the Shans. The finest 

 rubies go 10 Paris. 



In examining rubies the Shans never 

 use artificial light, holding that full 

 sunlight alone can bring out perfectly 



