428 NATURAL HISTORY. 



mental, always bring a higher price. Most exorbitant 

 sums are paid for diamonds, varying according to their 

 size, pure transparency, and lustrous sparkle. The 

 most remarkable diamonds are the following (the largest 

 one ever known was brought to the King of Portugal* 

 from Brazil, and uncut weighs 1680 grs., valued at 

 .5,644,800) : 



The Regent, which belongs to the crown of France, 

 weighs 136 carats ; that of the Great Mogul, cut, weighs 

 275 carats, valued at 5,500,000 florins ; that of the 

 Raja of Matun in Borneo, for a long time considered the 

 largest known, weighs 300 carats. 



Diamonds are regarded as the noblest and most bril- 

 liant of all gems, and jewellers cut and set them in many 

 shapes for ornamental purposes, as brilliants or rose dia- 

 monds. Diamond is the hardest known substance, and 

 can be cut or polished only by its own dust or powder ; 

 hence the common saying of " diamond cut diamond." 

 Fractured portions with good cutting edges are used for 

 various technical purposes, such as glaziers' cutting pen- 

 cils or pulverized for polishing other gems, beside being 

 employed in various ways in the arts. 



False diamonds, the preparation of which is accom- 

 plished with infinite skill by newly invented processes, 

 are sometimes substituted in place of the true, but the 

 imposition is easily detected, as, being so much softer, 

 they can be operated upon by a file made of good Eng- 

 lish steel. 



* Lately supposed to be a topaz. 



