126 



SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



special and distinctive names, and in most cases form part of the crown jewels of various 

 countries ; these famous stones will be described further on in a special section. 



TTie average size of diamonds found in different countries varies very considerably ; 

 formerly, when India and Brazil were the only localities at which diamonds were known to 

 exist, stones exceeding twenty carats in weight were of great rarity. During the most 

 productive period of the mines of Brazil, two or three years would elapse before a second 

 stone of this size would be found, while very few stones exceeding one hundred carats in 

 weight were ever found. The largest stone ever found in this locality, that known as the 

 " Star of the South " (Fig. 48), weighed in the rough 254|^ carats. The " Braganza," of the 

 Portuguese crown, said to weigh 1680 carats, would rank as the largest diamond ever found 



500 Carats. 



1000 Carats. 



iCarat. 



Fig. 32. Actual sizes of octahedral crystals of diamond of 1 to 1000 carats. 



in any locality were it indisputably a diamond ; the probabilities are, however, that it is a 

 fine piece of colourless topaz. 



The chances of obtaining large diamonds in the Indian deposits were more favourable, 

 a considerable number of diamonds exceeding one hundred ■ carats in weight having been 

 found there. Most of the large Indian diamonds are only known in their cut condition so 

 that their original weight can only be estimated. Of large Indian diamonds, known in the 

 rough condition in recent times, the "Regent" in the French crown jewels, is the heaviest; 

 it weighed before cutting 4l0 carats, and produced a beautiful brilliant of 136x3- carats. 

 Other large Indian stones are described below in the section on famous diamonds ; they are 

 comparatively few in number. The heaviest of the large diamonds of ancient times is known 

 as the " Great Mogul," which is said to have originally weighed 787J carats ; there is no 

 authentic information, however, either as to its weight or to its present whereabouts. The 

 island of Borneo has produced one or two large stones ; the largest reported diamond, 

 weighing 367 carats, is, however, like the " Braganza," almost certainly not diamond, and 

 probably nothing more valuable than a piece of rock-crystal. 



