502 ^ REPOKT OF NATIONAL MUSEUM, 1900. 



wciohing 136|| carats, the finest large diamond in the world. It 

 was discovered in India in 1701, and weighed 110 carats in the rough. 

 The finest bkie diamond is the ''Hope," an ahnost sapphire-blue stone 

 weighing Hi carats, valued at =£18,000. The " Dresden Green" is the 

 finest green diamond, a pear-shaped 18^ carat brilliant. The " Orloff" 

 is a 198-carat stone in the scepter of the Emperor of Russia, The 

 Russian treasury also contains the "Shah," an 86-carat stone. The 

 "Koh-i-Nur" or "mountain of light," which weighed, when first 

 brought to England, 180yV carats, but was reduced by recutting in 1852 

 to lOO^V carats, is among the English crown jewels. The "Victoria," 

 a Cape diamond weighing 457^ carats in the rough and 180 carats cut, 

 is valued at £200,000, and is perhaps the largest brilliant in the world. 

 The largest diamond in America, and the finest yellow diamond in the 

 world, is the "Tiffan}^" diamond, a flawless double-cut brilliant of a 

 rich orange-yellow color. It was found in South Africa, weighs 125f 

 carats, and is valued at $100,000. 



For a full discussion and history of the more important stones above 

 100 carats in weight, as well as of many others, see Streeter's Great 

 Diamonds of the World. 



The diamond occurs in alluvial deposits of gravel, sand, or clay, 

 associated with quartz, gold, platinum, zircon, rutile hematite, ilmenite, 

 chrysober}^, topaz, corundum, garnet, etc., the associated minerals 

 being those common in granite rocks or granitic veins. It is found 

 also in quartzose conglomerates, in peridotite veins in gneiss, and in an 

 eruptive pegmatite. 



Before the discovery of the Brazilian mines all diamonds 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 includes a large tract between 

 ^he Mahanadi and Godavari rivers; it embraces Sarnbalpui- and 

 Waigarh, 80 miles southeast of Nagpur as well as portions of the 

 province of (3hutia 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 Panna this conglomerate 

 appears to be largelj'^ made up of fragments of a lower sandstone which 

 it has been suggested may represent the original matrix. The yield 

 of the Indian mines, once so large, is at present very small. 



Borneo produces only about 3,000 carats annually. The principal 

 locality is in the basin of the Kapoeas River on the west side of the 

 Ratoos Mountain near the town of Pontianak. 



