46 BULLETIN 118, UNITED STATES NATIONAL MUSEUM. 



"Hope," an almost sapphire-blue stone, weighing 44| carats. The 

 "Dresden Green" is the finest green diamond, a pear-shaped 48i- 

 carat brilliant. The "Orloff," a 193-carat stone, was in the scepter 

 of the Emperor of Russia, The Russian treasury also contained the 

 "Shah," an 86-carat stone. The "Koh-i-Nur," or "mountain of 

 light," which weighed, when first brought to England, 186 T V carats, 

 but was reduced by recutting in 1852 to 106^ carats, is among 

 the English crown jewels. The "Victoria," a Cape diamond, weighed 

 457-} carats in the rough and 180 carats cut. The world's larg- 

 est diamonds, the "Excelsior" and the "Cullman," weighing in the 

 rough, respectively, 199.04 grams (995.2 carats) and 621.2 grams 

 (3,106 carats), are both South African, the former being found in 1893 

 and the latter in 1905. These have both been reduced in size by cut- 

 ting, and glass models of some of the resultant stones are included 

 in the collection of imitation stones. The largest diamond in America 

 at the present time and the finest yellow diamond in the world is the 

 "Tiffany," a flawless double-cut brilliant of a rich orange-yellow color. 

 It was found in South Africa and weighs 125| carats. 



Before the discovery of the Brazilian and African mines all dia- 

 monds were brought from India and Borneo. In India the diamond 

 is met with at three principal localities. The first is in southern India , 

 in the Madras Presidency, and embraces the districts of Kadapah, 

 Bellary, Karnul, Kistna, and Godavari. This region includes the 

 famous "Golconda" district, the name, however, being not that of 

 a mine, but merely the general term for the market where diamonds 

 were bought and sold. The second locality is farther north and in- 

 cludes a large tract between the Mahanadi and Godavari Rivers; it 

 embraces Sambalpur and Waigarh, 80 miles southeast of Nagpur, as 

 well as portions of the Province of Chutia Nagpur. The third region 

 is in Bundelkhand, in central India, the principal working being near 

 the city of Panna. The Indian diamonds were obtained in part from 

 alluvial deposits and in part from a quartzose conglomerate; at Panha 

 this conglomerate appears to be largely made up of fragments of a 

 lower sandstone, which it has been suggested may represent the origi- 

 nal matrix. The yield of the Indian mines, once so large, is at present 

 very small. The principal Borneo locality is in the basin of the 

 Kapoeas River, on the west side of the Ratoos Mountain, near the 

 town of Pontianak. 



The diamond deposits of Brazil were discovered in 1728 and were at 

 one time very productive, although the yield is at present small. Near 

 Diamantina in Minas Geraes the diamonds are obtained in part from 

 river washings and in part from prairie washings. The river deposits 

 consist of rolled quartz pebbles, mixed with or united by a ferrugi- 

 nous clay which rests usually on talcose clays. The more common 

 associated minerals are rutile, hematite, ilmenite, quartz, kyanite, 



